пятница, 2 ноября 2018 г.

Meteor Activity Outlook for November 3-9, 2018

Despite the thin cloudcover, Eliot Herman of Tucson, Arizona managed to capture this nice flaring Taurid fireball on November 1, 2018 at 09:26 UT

As seen from the northern hemisphere, meteor rates continue to be strong in November. While no major activity is expected this month, the two Taurid radiants plus the Leonids keep the skies active. The addition of strong sporadic rates make November one of the better months to view meteor activity from north of the equator. Skies are fairly quiet as seen from the southern hemisphere this month. Activity from the three showers mentioned above may be seen from south of the equator, but the sporadic rates are much lower than those seen in the northern hemisphere.


During this period the moon will reach its new phase on Wednesday November 7th. At this time the moon will be located near the sun and will be invisible at night. This weekend the waning crescent moon will rise during the early morning hours but will not cause any problems viewing meteors as long as you keep it out of your field of view. The estimated total hourly meteor rates for evening observers this week is near 4 for those viewing from the northern hemisphere and 3 for those located south of the equator. For morning observers the estimated total hourly rates should be near 24 as seen from mid-northern latitudes and 18 from the southern tropics. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity. Note that the hourly rates listed below are estimates as viewed from dark sky sites away from urban light sources. Observers viewing from urban areas will see less activity as only the brighter meteors will be visible from such locations.


The radiant (the area of the sky where meteors appear to shoot from) positions and rates listed below are exact for Saturday night/Sunday morning November 3/4. These positions do not change greatly day to day so the listed coordinates may be used during this entire period. Most star atlases (available at science stores and planetariums) will provide maps with grid lines of the celestial coordinates so that you may find out exactly where these positions are located in the sky. A planisphere or computer planetarium program is also useful in showing the sky at any time of night on any date of the year. Activity from each radiant is best seen when it is positioned highest in the sky, either due north or south along the meridian, depending on your latitude. It must be remembered that meteor activity is rarely seen at the radiant position. Rather they shoot outwards from the radiant so it is best to center your field of view so that the radiant lies at the edge and not the center. Viewing there will allow you to easily trace the path of each meteor back to the radiant (if it is a shower member) or in another direction if it is a sporadic. Meteor activity is not seen from radiants that are located far below the horizon. The positions below are listed in a west to east manner in order of right ascension (celestial longitude). The positions listed first are located further west therefore are accessible earlier in the night while those listed further down the list rise later in the night.





Radiant Positions at 8pm Local Standard Time


Radiant Positions at 20:00

Local Standard Time






Radiant Positions at 12:00 Local Standard Time


Radiant Positions at 00:00

Local Standard Time






Radiant Positions at 5am Local Standard Time


Radiant Positions at 4:00

Local Standard Time





These sources of meteoric activity are expected to be active this week.


The Andromedids (AND) reach maximum activity on November 5th. At that time the radiant will be located near 01:23 (021) +28 . This position lies on the border of Triangulum and Pisces, 4 degrees southwest of the 3rd magnitude star known as Mothallah (Alpha Trianguli). This part of the sky is best placed near 2200 (10pm) Local Standard Time (LST), when the radiant lies highest above the horizon. This is a famous shower that produced some brilliant displays during the 19th century. Since then the main orbit of the particles from comet 3D/Biela have moved away from the Earth. Still, remnants may be seen from October 26 through November 17. Current rates would most likely be near 1 per hour as seen from the northern hemisphere and less than 1 as seen south of the equator. With an entry velocity of 19 km/sec., the average Andromedid meteor would be of very slow velocity.


The Northern Taurids (NTA) are active from a large radiant located near 03:24 (051) +21. This position lies in eastern Aries, 3 degrees northeast of the 4th magnitude star known as Botein (delta Arietis). Rates at this time should be near 5 per hour as seen from the northern hemisphere and 4 as seen south of the equator. Like its southern counterpart, these meteors may be seen all night long but the radiant is best placed near midnight LST when it lies on the meridian and is located highest in the sky. With an entry velocity of 28 km/sec., the average Northern Taurid meteor would be of slow velocity.


The Southern Taurids (STA) are also active from a large radiant centered near 03:36 (054) +14. This position lies in western Taurus, 10 degrees southwest of the Pleiades. These meteors may be seen all night long but the radiant is best placed near midnight LST when it lies on the meridian and is located highest in the sky. Rates at this time should be near 4 per hour regardless of your location. With an entry velocity of 29 km/sec., the average Southern Taurid meteor would be of slow velocity.


The omicron Eridanids (OER) were discovered by Japanese observers using video data from SonotoCo in 2007-2008. The activity period ranges from October 16 – November 24 with maximum activity occurring on November 4th. This is a weak shower that usually produces rates less than 1 per hour, even at maximum activity. The radiant is currently located at 03:36 (054) -02, which places it in  northwestern Eridanus 10 degrees southeast of the 3rd magnitude star known as Menkar (alpha Ceti). This location is close to the source of the Southern Taurids so care must be taken to separate these meteors. Like the STA’s these meteors may be seen all night long but the radiant is best placed near 0100 LST when it lies on the meridian and is located highest in the sky. With an entry velocity of 29 km/sec., the average omicron Eridanid meteor would be of slow velocity.


The chi Taurids (CTA) were discovered by Dr. Peter Brown  during his 7 year survey using the Canadian Meteor Orbit Radar (CMOR). This source is active from October 20 through November 17 with a maximum occurring near November 3rd. Current rates should be near 1 per hour as seen from the northern hemisphere and less than 1 as seen from south of the equator. The radiant is currently located at 04:16 (064) +26, which places it in western Taurus , 5 degrees east of the famous naked eye open cluster known as the Pleiades. This location is close to the source of the Northern Taurids so care must be taken to separate these meteors. These meteors may be seen all night long but the radiant is best placed near 0200 LST when it lies on the meridian and is located highest in the sky. With an entry velocity of 41 km/sec., the average chi Taurid meteor would be of medium velocity.


The Orionids (ORI) are still active from a radiant located at 07:17 (109) +15. This area of the sky lies in southern Gemini, 2 degrees south of the 4th magnitude star known as lambda Geminorum. This area of the sky is best placed near 0400 LST, when it lies highest above the horizon. Rates should be near 3 per hour no matter your location. With an entry velocity of 67 km/sec., most activity from this radiant would be of swift speed.


The nu Eridanids (NUE) were co-discovered by Japanese observers using SonotoCo and Juergen Rendtel and Sirko Molau of the IMO. Activity from this long-period stream stretches from August 23 all the way to November 16. A very shallow maximum occurred near September 24. The radiant currently lies at 07:44 (116) +14, which places it on the Gemini/Canis Minoir border, 9 degrees north of the zero magnitude star known as Procyon (alpha Canis Minoris). This area of the sky is best seen during the last dark hour before dawn when the radiant lies highest in a dark sky. Current rates are expected to be less than 1 per hour during this period no matter your location. With an entry velocity of 67 km/sec., the average meteor from this source would be of swift velocity. Some experts feel that these meteors are related to the Orionid shower, which peaked on October 22.


The first Leonids (LEO) of the season should begin appearing this weekend from a radiant located at located at 09:24 (141) +27. This position lies in northwestern Leo, just east of the 4th magnitude star known as Al Min’ħar al A’sad (kappa Leonis). Current rates are expected to be near 1 shower member per hour during the late morning hours as seen from the northern hemisphere. Hourly rates from south of the equator would be less than 1. Maximum is predicted to occur on November 17. The Leonid radiant is best placed during the last hour before morning twilight when the radiant lies highest in a dark sky. Leonids may be seen from the southern hemisphere but the viewing conditions are not quite as favorable as those north of the equator. With an entry velocity of 70 km/sec., most activity from this radiant would be of swift speed with numerous persistent trains on the brighter meteors.


The kappa Ursae Majorids (KUM) were discovered by cameras of the SonotaCo network in Japan during an outburst of activity on November 5, 2009. This radiant is active from November 3-10 with maximum activity occurring on the 7th. At maximum the radiant is located at 09:49 (147) +45. This position lies in southeastern Ursa Majoris, 7 degrees southeast of the 3rd magnitude star known as theta Ursae Majoris. Rates, even at maximum, are expected to be less than 1 regardless of your location. These meteors are best seen during the last hour before dawn when the radiant lies highest above the horizon in a dark sky. With an entry velocity of 66 km/sec., the average Kappa Ursae Majorid meteor would be of swift velocity.


The last of the Leonis Minorids (LMI) are expected this week. These meteors are active from October 12-Nov 5 with maximum activity occurring on October 22nd. This radiant is currently located at 11:32 (173) +32, which places it in southern Ursae Majoris, 2 degrees southeast of the 3rd magnitude star known as Alula Borealis (nu Ursae Majoris). The radiant is best placed just before dawn when it lies highest in a dark sky. This shower is better situated for observers situated in the northern hemisphere where the radiant rises far higher into the sky before the start of morning twilight. Current rates would be less than 1 no matter your location. At 62km/sec., the average Leonis Minorid is swift. From my personal experience this minor shower produces a high proportion of bright meteors.


As seen from the mid-northern hemisphere (45N) one would expect to see approximately 10 sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near 3 per hour. As seen from the tropical southern latitudes (25S), morning rates would be near 7 per hour as seen from rural observing sites and 2 per hour during the evening hours. Locations between these two extremes would see activity between the listed figures.


The table below presents a list of radiants that are expected to be active this week. Rates and positions are exact for Saturday night/Sunday morning except where noted in the shower descriptions.

















































































































SHOWER DATE OF MAXIMUM ACTIVITY CELESTIAL POSITION ENTRY VELOCITY CULMINATION HOURLY RATE CLASS
RA (RA in Deg.) DEC Km/Sec Local Standard Time North-South
Andromedids (AND) Nov 05 01:23 (021) +28 18 22:00 1 – <1 III
Northern Taurids (NTA) Nov 02 03:24 (051) +21 28 00:00 5 – 4 II
Southern Taurids (STA) Oct 29-Nov 03 03:36 (054) +14 27 00:00 4 – 4 II
omicron Eridanids (OER) Nov 04 03:36 (054) -02 29 00:00 <1 – <1 IV
chi Taurids (CTA) Nov 03 04:16 (064) +26 41 01:00 1 – <1 IV
Orionids (ORI) Oct 22 07:17 (109) +15 67 04:00 3 – 3 I
nu Eridanids (NUE) Sep 24 07:44 (116) +14 67 04:00 <1 – <1 IV
Leonids (LEO) Nov 17 09:24 (141) +27 70 07:00 <1 – <1 I
kappa Ursae Majorids (KUM) Nov 07 09:49 (147) +45 66 07:00 <1 – <1 IV
Leonis Minorids (LMI) Oct 22 11:32 (173) +32 62 09:00 <1 – <1 II

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China launches first geostationary BeiDou-3 satellite


BeiDou Navigation Satellite System logo.


Nov. 2, 2018



Long March-3B carrying BeiDou-3 GEO-1 launch

A Long March-3B (Chang Zheng-3) rocket launched the first geostationary BeiDou-3 navigation satellite from the Xichang Satellite Launch Center, Sichuan Province, southwest China, on 1 November 2018, at 15:57 UTC (23:57 local time).



BeiDou-3 GEO-1 – the first geostationary BeiDou-3 satellite

BeiDou-3 GEO-1 is the 41st BeiDou navigation satellite and the first geostationary orbit satellite of the BeiDou-3 system. This is the 17th satellite for the BeiDou-3 system, with 18 BeiDou-3 satellites expected to be orbiting by the end of the year.



 BeiDou-3 GEO-1

The satellite will use its own engine to circularize its orbit over the equator in the coming weeks, settling into a position in geostationary orbit, where its speed will match the rate of Earth’s rotation, allowing the Beidou spacecraft to remain over the same geographic region.



Beidou Constellation

The Beidou network has provided regional navigation services over the Asia-Pacific since the end of 2012, and China plans to roll out a wider coverage zone stretching over Asia, Europe and most of Africa at the end of this year. Global service is planned around 2020 once the constellation contains more than 30 satellites.


For more information about China Aerospace Science and Technology Corporation (CASC), visit: http://english.spacechina.com/n16421/index.html


For more information about China National Space Administration (CNSA), visit: http://www.cnsa.gov.cn/


For more information about Beidou navigation system: http://www.beidou.gov.cn/


Images, Video, Text, Credits: CASC/CNSA/IGS/CCTV/SciNews.


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Devils Postpile National Monument | #Geology #GeologyPage…


Devils Postpile National Monument | #Geology #GeologyPage #California #USA


Devils Postpile National Monument is located near Mammoth Mountain in eastern California. The national monument protects Devil’s Postpile, an unusual rock formation of columnar basalt.


Read more & More Photos: http://www.geologypage.com/2017/03/devils-postpile-national-monument.html


Geology Page

www.geologypage.com

https://www.instagram.com/p/Bprc7KRlMlx/?utm_source=ig_tumblr_share&igshid=1sa7u4vbs9uou


Austinite (variety cuprian) with Calcite | #Geology #GeologyPage…


Austinite (variety cuprian) with Calcite | #Geology #GeologyPage #Mineral


Locality: Ojuela Mine, Mapimí, Municipio Mapimí, Durango Mexico


Specimen size: 5 × 4.5 × 3.2 cm


Photo Copyright © Fabre Minerals


Geology Page

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https://www.instagram.com/p/BpreSahFP8m/?utm_source=ig_tumblr_share&igshid=5n5xwubh06da


Chalcanthite | #Geology #GeologyPage #Mineral Locality: Planet…


Chalcanthite | #Geology #GeologyPage #Mineral


Locality: Planet Mine, La Paz County, Arizona, United States of America


Size: 2.1 × 1.7 × 0.7 cm


Photo Copyright © Viamineralia /e-rocks.com


Geology Page

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https://www.instagram.com/p/Bpreo2nlVKJ/?utm_source=ig_tumblr_share&igshid=148k62sr9350a


Devils Tower | #Geology #GeologyPage #DevilsTower…


Devils Tower | #Geology #GeologyPage #DevilsTower #UnitedStates


Devils Tower was the first declared United States National Monument, established on September 24, 1906, by President Theodore Roosevelt. The Monument’s boundary encloses an area of 1,347 acres (545 ha).


Read more & More Photos: http://www.geologypage.com/2016/05/devils-tower.html


Geology Page

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Bouleia dagincourti trilobite | #Geology #GeologyPage #Trilobite…


Bouleia dagincourti trilobite | #Geology #GeologyPage #Trilobite #Fossil


Age: Devonian

Location: Belen Formation, La Paz, Bolivia

Size: 3 cm


Photo Copyright © American Museum of Natural History


Geology Page

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Malachite | #Geology #GeologyPage #Mineral Locality: Clara…


Malachite | #Geology #GeologyPage #Mineral


Locality: Clara Mine, Wolfach, Black Forest, Baden-Württemberg, Germany


Size: 2.4 × 3 × 2 cm


Photo Copyright © Mintreasure /e-rocks.com


Geology Page

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Optical Communications: Explore Lasers in Space

image

When we return to the Moon, much will seem unchanged since

humans first arrived in 1969. The flags placed by Apollo

astronauts will be untouched by any breeze. The footprints left by man’s “small

step” on its surface will still be visible across the Moon’s dusty landscape.


Our next generation of lunar explorers will require

pioneering innovation alongside proven communications technologies. We’re

developing groundbreaking technologies to help these astronauts fulfill their

missions.


In space communications networks, lasers will supplement

traditional radio communications, providing an advancement these explorers

require. The technology, called optical communications, has been in development

by our engineers over decades.


image

Optical

communications
, in infrared, has a higher frequency than radio,

allowing more data to be encoded into each transmission. Optical communications

systems also have reduced size, weight and power requirements. A smaller system

leaves more room for science instruments; a weight reduction can mean a less

expensive launch, and reduced power allows batteries to last longer.


image

On the path through this “Decade of Light,” where laser

joins radio to enable mission success, we must test and demonstrate a number of

optical communications innovations.


image

The Laser Communications Relay Demonstration

(LCRD) mission will send data between ground stations in Hawaii and California

through a spacecraft in an orbit stationary relative to Earth’s rotation. The

demo will be an important first step in developing next-generation Earth-relay

satellites that can support instruments generating too much data for today’s

networks to handle.


image

The Integrated LCRD Low-Earth Orbit User Modem

and Amplifier-Terminal
will provide the International

Space Station
with a fully operational optical communications

system. It will communicate data from the space station to the ground through

LCRD. The mission applies technologies from previous optical communications

missions for practical use in human spaceflight.


image

In deep space, we’re working to prove laser technologies

with our Deep Space

Optical Communications
mission. A laser’s wavelength is smaller than

radio, leaving less margin for error in pointing back at Earth from very, very

far away. Additionally, as the time it takes for data to reach Earth increases,

satellites need to point ahead to make sure the beam reaches the right spot at

the right time. The Deep Space Optical Communications mission will ensure that

our communications engineers can meet those challenges head-on.


image

An integral part of our journey back to the Moon will be our

Orion

spacecraft
. It looks remarkably similar to the Apollo capsule, yet it

hosts cutting-edge technologies. NASA’s Laser Enhanced Mission Communications

Navigation and Operational Services (LEMNOS) will provide Orion with data rates

as much as 100 times higher than current systems.


LEMNOS’s optical terminal, the Orion EM-2 Optical

Communications System, will enable live, 4K ultra-high-definition video from

the Moon. By comparison, early Apollo cameras filmed only 10 frames per second

in grainy black-and-white. Optical communications will provide a “giant leap”

in communications technology, joining radio for NASA’s return to the Moon and the

journey beyond.


image

NASA’s Space

Communications and Navigation program office provides strategic oversight to optical

communications research. At NASA’s Goddard Space Flight Center in Greenbelt,

Maryland, the Exploration and Space Communications projects division is guiding

a number of optical communications technologies from infancy to fruition. If

you’re ever near Goddard, stop by our visitor center to check out our new

optical communications exhibit. For more information, visit nasa.gov/SCaN

and esc.gsfc.nasa.gov.


2018 November 2 Cygnus Shell Supernova Remnant W63 Image…


2018 November 2


Cygnus Shell Supernova Remnant W63
Image Credit & Copyright: J-P Metsavainio (Astro Anarchy)


Explanation: The ghost of a long-dead star, the W63 supernova remnant shines like a faint cosmic smoke-ring along the plane of the Milky Way galaxy toward the northern constellation Cygnus the swan. Its wraithlike appearance is traced against the region’s rich complex of interstellar clouds and dust by an eerie blue glow. Spanning over four full moons on the sky, the beautiful image is a telescopic mosaic in twelve panels that combines 100 hours of exposure time using narrow band filters. It shows characteristic light from ionized atoms of sulfur, hydrogen and oxygen in red, green, and blue hues. Likely over 5,000 light-years away, the visible part of the still expanding shell supernova remnant is around 150 light-years in diameter. So far no source has been identified as with the remains of W63’s original star. Light from the star’s supernova explosion would have reached Earth over 15,000 years ago.


∞ Source: apod.nasa.gov/apod/ap181102.html


OSIRIS-REx Captures ‘Super-Resolution’ View of Bennu


NASA – OSIRIS-REx Mission patch.


Nov. 1, 2018



This “super-resolution” view of asteroid Bennu was created using eight images obtained by NASA’s OSIRIS-REx spacecraft on Oct. 29, 2018, from a distance of about 205 miles (330 km). The spacecraft was moving as it captured the images with the PolyCam camera, and Bennu rotated 1.2 degrees during the nearly one minute that elapsed between the first and the last snapshot. The team used a super-resolution algorithm to combine the eight images and produce a higher resolution view of the asteroid. Bennu occupies about 100 pixels and is oriented with its north pole at the top of the image.


OSIRIS-REx (Origins Spectral Interpretation Resource Identification Security Regolith Explorer): http://www.nasa.gov/mission_pages/osiris-rex/index.html


Image, Text, Credits: NASA/Karl Hille/Goddard/University of Arizona.


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Dramatic on-board video shows moment of Soyuz booster failure on October 11, 2018


ROSCOSMOS logo.


November 01, 2018


New video released by the Russian space agency Thursday shows the moment a Soyuz rocket ran into trouble around two minutes after liftoff with a two-man crew Oct. 11, when one of the vehicle’s four first stage boosters crashed into the Soyuz core stage.



Image above: The Soyuz MS-10 spacecraft launched Oct. 11, 2018, with Expedition 57 crew members Nick Hague of NASA and Alexey Ovchinin of Roscosmos. During the Soyuz spacecraft’s climb to orbit, an anomaly occurred, resulting in an abort downrange. The crew was quickly recovered in good condition. Image Credits: NASA/Roscosmos.


An on-board safety system immediately detected the malfunction, triggering an automatic abort with escape rockets that pushed the Soyuz MS-10 spacecraft with Russia cosmonaut Alexey Ovchinin and NASA astronaut Nick Hague safely away from the rocket.


The crew landed downrange on the steppe of Kazakhstan after the first use of the Soyuz crew escape system since 1983.


The video from a rear-facing camera on the Soyuz-FG rocket shows the kerosene-fueled launcher lifting off from the Baikonur Cosmodrome in Kazakhstan, followed by a sped-up video sequence during the rocket’s initial climb. The video then reverts to a real-time sequence before the separation of the four strap-on boosters from the core stage.



Dramatic on-board video shows moment of Soyuz booster failure

The boosters are supposed to separate simultaneously, but one of the units appears to cling to the center stage in the video, before colliding with the core section, causing the rocket to veer out of control.


Russian investigators announced Thursday that the Oct. 11 failure was caused by a “deformed” sensor in the booster separation system. Read more details in our full story on the investigation’s results.


Roscosmos. Press-conference on the findings of the State Committee investigation of the Soyuz failure of October 11, 2018: http://en.roscosmos.ru/20752/


Related articles:


Rocket Investigation Complete; Russia, Japan Announce Mission Updates:
https://orbiterchspacenews.blogspot.com/2018/11/rocket-investigation-complete-russia.html


Crew in Good Condition After Booster Failure:
https://orbiterchspacenews.blogspot.com/2018/10/crew-in-good-condition-after-booster.html


Soyuz MS-10 – Emergency landing after a failure:
https://orbiterchspacenews.blogspot.com/2018/10/soyuz-ms-10-emergency-landing-after.html


Related links:


Roscosmos investigator report: https://www.youtube.com/watch?v=PzLBGGsOOps&t=31s


Roscosmos statement: https://www.roscosmos.ru/25664/


Roscosmos: https://www.roscosmos.ru/


NASA: https://www.nasa.gov/


Image (mentioned), Video, Text, Credits: Roscosmos/NASA/Spaceflight Now.com/Stephen Clark.


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Studying Lyman-α-galaxies with strong gravitational lensing


Images by the Hubble Space telescope of all gravitational lens systems. The surface brightness scale is in electrons per second. The lensing morphologies are quite varied, from nearly complete Einstein rings to very compact 2-image systems. © MPA


Strong gravitational lensing is an extremely powerful tool to go beyond the current limits in angular resolution and to investigate the high-redshift, i.e. distant Universe. Scientists at MPA take advantage of this phenomenon to perform a detailed study of 17 Lyman-α-galaxies and present an analysis of the sizes and star formation rates of their reconstructed ultra-violet (UV) continuum emission.


Lyman-α-emitting (LAE) galaxies represent a unique probe of the young Universe, about 1 to 2 billion years after the Big Bang. Typical LAEs are characterised by high-ionisation and strong star formation with low metallicity (i.e. few elements heavier than hydrogen and in general a low mass. The Lyman-α emission is produced when electrons recombine with the ionized hydrogen atoms and the properties cited above, combined with low dust content, allow for the escape of a significant fraction of these photons. While this emission is thought to have had a crucial role in the reionisation of the young Universe, very little is known about the detailed structure of these galaxies and, most importantly, about the mechanism that leads to the production of these high-energy photons.


So far the study of these high-redshift objects has been limited to quantifying the properties of their strong optical lines. Alternatively, many efforts have been spent to identify local analogues, i.e. nearby galaxies presenting similar physical and morphological characteristics. Both these approaches, however, require significant investment in telescope time.



These images show the lens model of one of the systems in the sample showing the actual data, the model, normalized residuals, and the reconstruction of the source (from left). Critical curves and caustics are plotted in grey. © MPA


Another resource to study these galaxies lies in high-resolution imaging studies that so far have been very useful to reveal their structure. LAEs are found to be quite compact objects and there is no evidence that they change their size as they evolve. Moreover they are surrounded by a large Lyman-α-emitting halo which is on average 10 times more extended than the UV continuum emitting region. Also this halo does not show an evolution in size with redshift. However, such studies are currently limited by the angular resolution of the observations and struggle to reveal the detailed structure of these objects.


Strong gravitational lensing can be used to overcome these limits. The first statistically significant sample of LAEs at z~2.5 strongly lensed by early type galaxies at z~0.5, has recently been revealed by observations with the Hubble Space Telescope. Due to the lensing magnification by a factor of about 20, we can access and probe the detailed structure of these galaxies at scales around 100 pc (some 300 light-years).



The star-formation rate intensity of the objects from Fig. 1, based on the source reconstructions from the grid-based gravitational lens modelling. The colour-scale for each object is in units of solar masses per year in a square with 1 kiloparsec on the side. (The reconstruction of the object J0201+3228 was not included as this presented strong residuals.) © MPA


We have studied the intrinsic properties of the UV-continuum emission of these LAEs and we found that they have a median star formation rate of 1.4 solar masses per year with peaks of up to 54 solar masses per year. (This is actually a lower limit as we could not correct for dust attenuation.) We have found these galaxies to be quite compact, with a median size of about 500 pc and a range of radii from 200 to 1800 pc – our Milky Way with about 60 000 pc is gigantic compared to these LAE. Interestingly, they show quite complex morphologies with several compact and diffuse components, while in some cases they appear to be interacting. In two cases (14 percent of 17?) the galaxies seem to have off-axis components that may be associated with mergers.


Most interestingly, our LAEs are found to be quite elliptical, with a mean axis-ratio of about 0.5. This morphology is consistent with disk-like structures of star-formation for three-quarters of our sample, which would rule out models where the Lyman-α-emission is only seen perpendicular to the disk to favour instead clumpy models. Our results are in agreement with the studies of non-lensed LAEs at similar redshifts, but are more robust given the improved angular resolution of our analysis and given that no stacking techniques are needed.


With 200 pc, our lower limit on the intrinsic size of these objects is a factor of two smaller than what is achieved in non-lensed LAEs studies. In general our analysis further promotes gravitational lensing as a powerful tool to analyse and resolve the detailed structure of high-redshift galaxies, allowing the study of their physical and morphological properties at a resolution otherwise only achievable with nearby targets.

Authors


Ritondale, Elisa
PhD student
Phone: 2233
Email: elisa@mpa-garching.mpg.de
Room: 252


Vegetti, Simona
Scientific Staff
Phone: 2285
Email: svegetti@mpa-garching.mpg.de





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Big deal of 2018: Yamnaya not related to Maykop

I was going to write this post after the genotype data from the Wang et al. preprint on the genetic prehistory of the Greater Caucasus became available, because I wanted to demonstrate a few key points with analyses of my own. But I’ve got a hunch that the formal publication of the manuscript, and thus also the release of the data, has been indefinitely delayed for one reason or another. So here goes anyway, the big deal of 2018…
This year, ancient DNA has revealed that the populations associated with the Maykop and Yamnaya archeological cultures were genetically distinct from each other, and, in all likelihood, didn’t mix to any significant degree. Case in point: an ADMIXTURE analysis from Wang et al. 2018.



No doubt, this is quite a shock for many people, especially those of you who consider Maykop to have been a Proto-Indo-European-speaking culture that either gave rise to Yamnaya or at least Indo-Europeanized it. So now, if you still want to see Maykop as the Indo-Europeanizing agent in the Pontic-Caspian steppe, you’ll have to rely solely on archeological and linguistics data, and also keep in mind that ancient DNA has slapped you in the face.
In just a few years, ancient DNA has provided us with plenty of shocks, but this is arguably among the biggest.
However, I honestly can’t say that it was a huge surprise for me, because I tentatively predicted this outcome more than two years ago based on a handful of mitochondrial (mtDNA) haplotypes (see here). Certainly, analyzing genome-wide genetic data is what I thrive on, but if that’s off limits, then I find that eyeballing even a few mtDNA haplotypes can be very useful too.
Wang et al. easily demonstrate the lack of any meaningful genetic relationship between Maykop (including Steppe Maykop, which shows an unusual eastern influence) and Yamnaya using a range of methods. But, judging by their conclusion, in which they still seem to want to see Maykop as the said Indo-Europeanizing agent in the Pontic-Caspian steppe, they’re not exactly enthused by their own results. And they make the following claim (emphasis is mine):



Based on PCA and ADMIXTURE plots we observe two distinct genetic clusters: one cluster falls with previously published ancient individuals from the West Eurasian steppe (hence termed ‘Steppe’), and the second clusters with present-day southern Caucasian populations and ancient Bronze Age individuals from today’s Armenia (henceforth called ‘Caucasus’), while a few individuals take on intermediate positions between the two. The stark distinction seen in our temporal transect is also visible in the Y-chromosome haplogroup distribution, with R1/R1b1 and Q1a2 types in the Steppe and L, J, and G2 types in the Caucasus cluster (Fig. 3A, Supplementary Data 1). In contrast, the mitochondrial haplogroup distribution is more diverse and almost identical in both groups (Fig. 3B, Supplementary Data 1).



I’d say that what they’re almost suggesting there is that the Caucasus and Steppe clusters, hence also the Maykop and Yamnaya populations, shared significant maternal ancestry. If this were true, then perhaps it might mean that the Pontic-Caspian steppe was Indo-Europeanized via female-biased migrations from Maykop? Yes, perhaps, if this were true. However, it’s not.
To be sure, Yamnaya does show a close genome-wide genetic relationship with an earlier group from the North Caucasus region: the so called Eneolithic steppe people. But they can’t be linked to Maykop or even the roughly contemporaneous nearby Eneolithic Caucasus population, and seem to have vanished, at least as a coherent genetic unit, just as Maykop got going. Wang et al. managed to sequence three Eneolithic steppe samples with the following mtDNA haplogroups: H2, I3a and T2a1b.
H2 is too broad a haplotype to bother with, but here are the results for I3a and T2a1b from the recently launched AmtDB, the first database of ancient human mitochondrial genomes (see here).




In a database of 1,131 ancient samples, I3a shows up in just five individuals, all of them associated with Yamnaya-related archeological cultures and populations: Poltavka (BARu), Unetice (UNC), Corded Ware (CWC), and Bell Beaker (BBC). Similarly, T2a1b shows up in just four individuals, all of them associated with Corded Ware (CWC) and Bell Beaker-derived Bronze Age Britons (BABI). And if I go back a step to T2a1, then the list reveals two Yamnaya individuals from what is now Kalmykia, Russia.
Thus, using just two mtDNA haplotypes I’m able to corroborate the results from genome-wide genetic data showing a close relationship between Eneolithic steppe and Yamnaya. So like I said, useful stuff.
This obviously begs the question: what does the AmtDB reveal about Maykop mtDNA haplotypes, especially in the context of the genetic relationship, or rather lack of, between Yamnaya and Maykop? Yep, again, the AmtDB basically corroborates the results from genome-wide genetic data.
But don’t take my word for it. Stick the currently available Maykop mtDNA haplogroups into the AmtDB and see what happens (for your convenience I’ve made a list available here). Considering the close geographic and temporal proximity of Maykop to Yamnaya, you won’t see an overly high sharing rate with Yamnaya and closely related populations. Moreover, Maykop shows several haplogroups that appear highly unusual in the context of the Eneolithic and Bronze Age steppe mtDNA gene pool, and, instead, link its maternal ancestry to those of the early European farmers, West Asians or even Central Asians, such as HV, M52, U1b, U7b and X2f.
See also…
Steppe Maykop: a buffer zone?
Yamnaya isn’t from Iran just like R1a isn’t from India
Big deal of 2016: the territory of present-day Iran cannot be the Indo-European homeland

Source


NASA’s Dawn Mission to Asteroid Belt Comes to End


NASA – Dawn Mission patch.


Nov. 1, 2018


NASA’s Dawn spacecraft has gone silent, ending a historic mission that studied time capsules from the solar system’s earliest chapter.



Dusk for Dawn: NASA Mission to the Asteroid Belt

Vvideo above: NASA’s Dawn spacecraft turned science fiction into science fact by using ion propulsion to explore the two largest bodies in the main asteroid belt, Vesta and Ceres. The mission will end this fall, when the spacecraft runs out of hydrazine, which keeps it oriented and in communication with Earth. Video Credits: NASA/JPL-Caltech.


Dawn missed scheduled communications sessions with NASA’s Deep Space Network on Wednesday, Oct. 31, and Thursday, Nov. 1. After the flight team eliminated other possible causes for the missed communications, mission managers concluded that the spacecraft finally ran out of hydrazine, the fuel that enables the spacecraft to control its pointing. Dawn can no longer keep its antennas trained on Earth to communicate with mission control or turn its solar panels to the Sun to recharge.



Image above: This photo of Ceres and the bright regions of Occator Crater was one of the last views NASA’s Dawn spacecraft transmitted before it completed its mission. This view, which faces south, was captured on Sept. 1, 2018, at an altitude of 2,340 miles (3,370 kilometers) as the spacecraft was ascending in its elliptical orbit. Image Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.


The Dawn spacecraft launched 11 years ago to visit the two largest objects in the main asteroid belt. Currently, it’s in orbit around the dwarf planet Ceres, where it will remain for decades.


“Today, we celebrate the end of our Dawn mission – its incredible technical achievements, the vital science it gave us, and the entire team who enabled the spacecraft to make these discoveries,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate in Washington. “The astounding images and data that Dawn collected from Vesta and Ceres are critical to understanding the history and evolution of our solar system.”


Dawn launched in 2007 on a journey that put about 4.3 billion miles (6.9 billion kilometers) on its odometer. Propelled by ion engines, the spacecraft achieved many firsts along the way. In 2011, when Dawn arrived at Vesta, the second largest world in the main asteroid belt, the spacecraft became the first to orbit a body in the region between Mars and Jupiter. In 2015, when Dawn went into orbit around Ceres, a dwarf planet that is also the largest world in the asteroid belt, the mission became the first to visit a dwarf planet and go into orbit around two destinations beyond Earth.



Image above: This photo of Ceres and one of its key landmarks, Ahuna Mons, was one of the last views Dawn transmitted before it completed its mission. This view, which faces south, was captured on Sept. 1, 2018, at an altitude of 2220 miles (3570 kilometers) as the spacecraft was ascending in its elliptical orbit. Image Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.


“The fact that my car’s license plate frame proclaims, ‘My other vehicle is in the main asteroid belt,’ shows how much pride I take in Dawn,” said Mission Director and Chief Engineer Marc Rayman at NASA’s Jet Propulsion Laboratory (JPL). “The demands we put on Dawn were tremendous, but it met the challenge every time. It’s hard to say goodbye to this amazing spaceship, but it’s time.”


The data Dawn beamed back to Earth from its four science experiments enabled scientists to compare two planet-like worlds that evolved very differently. Among its accomplishments, Dawn showed how important location was to the way objects in the early solar system formed and evolved. Dawn also reinforced the idea that dwarf planets could have hosted oceans over a significant part of their history – and potentially still do.


“In many ways, Dawn’s legacy i­s just beginning,” said Princ­­ipal Investigator Carol Raymond at JPL. “Dawn’s data sets will be deeply mined by scientists working on how planets grow and differentiate, and when and where life could have formed in our solar system. Ceres and Vesta are important to the study of distant planetary systems, too, as they provide a glimpse of the conditions that may exist around young stars.”



Dawn Ceres. flyby Mage Credits: NASA/JPL-Caltech

Because Ceres has conditions of interest to scientists who study chemistry that leads to the development of life, NASA follows strict planetary protection protocols for the disposal of the Dawn spacecraft. Dawn will remain in orbit for at least 20 years, and engineers have more than 99 percent confidence the orbit will last for at least 50 years.


So, while the mission plan doesn’t provide the closure of a final, fiery plunge – the way NASA’s Cassini spacecraft ended last year, for example – at least this is certain: Dawn spent every last drop of hydrazine making science observations of Ceres and radioing them back so we could learn more about the solar system we call home.


The Dawn mission is managed by JPL for NASA’s Science Mission Directorate in Washington. Dawn is a project of the directorate’s Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama. JPL is responsible for overall Dawn mission science. Northrop Grumman in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.


Related article:


The Surprising Coincidence Between Two Overarchieving NASA Missions:
https://orbiterchspacenews.blogspot.com/2018/10/the-surprising-coincidence-between-two.html


Check out the Dawn media toolkit, with a mission timeline, images, video and quick facts, at:


https://dawn.jpl.nasa.gov/mission/toolkit


Watch the video “Dawn: Mission to Small Worlds,” with NASA Chief Scientist Jim Green, at:


https://www.youtube.com/watch?v=JrafypeEhTM


More information about Dawn is available at: https://www.nasa.gov/dawn


Images (mentioned), Video (mentioned), Text, Credits: NASA/Dwayne Brown/JoAnna Wendel/Karen Northon/JPL/Gretchen McCartney.


Greetings, Orbiter.chArchive link


Rocket Investigation Complete; Russia, Japan Announce Mission Updates


ISS – Expedition 57 Mission patch.


November 1, 2018


NASA is working closely with its International Space Station partner Roscosmos to move forward on crew launch plans. Roscosmos plans to launch the Progress 71 resupply mission on Nov. 16, and is targeting the launch of the Expedition 58 crew including NASA astronaut Anne McClain for Dec. 3, pending the outcome of the flight readiness review.



Image above: The Soyuz MS-10 spacecraft launched Oct. 11, 2018, with Expedition 57 crew members Nick Hague of NASA and Alexey Ovchinin of Roscosmos. During the Soyuz spacecraft’s climb to orbit, an anomaly occurred, resulting in an abort downrange. The crew was quickly recovered in good condition. Image Credits: NASA/Roscosmos.


Roscosmos completed an investigation into the loss of a Soyuz rocket last month that led to a suspension of Russian rocket launches to the station. One of four first stage rocket engines abnormally separated and hit the second stage rocket that led to the loss of stabilization of the Soyuz on Oct. 11. A statement from Roscosmos describes the cause…


“The reason for the abnormal separation is the non-opening of the nozzle cap of the “D” block oxidizer tank because of the deformation of the stem of the separation contact sensor (bending on 6 ˚ 45 ‘), which was admitted when assembling the “package” at the Baikonur Cosmodrome. The cause of the LV accident is of operational nature and extends to the backlog of the “Soyuz” type LV “package”.


Japan also announced today the release of its H-II Transfer Vehicle-7 (HTV-7) resupply ship, also called the Kounotori, from the station’s Harmony module. Commander Alexander Gerst will command the Canadarm2 robotic arm to release Kounotori Nov. 7 at 10:50 a.m. EDT as Flight Engineer Serena Auñón-Chancellor supports him.



Image above: A Japan Aerospace Exploration Agency (JAXA) Kounotori 5 H-II Transfer Vehicle (HTV-5) is seen through the window shortly before release from the International Space Station in September 2015. Image Credits: NASA/JAXA/Kimiya Yui.


Named “Kounotori,” or “white stork” in Japanese, the unpiloted cargo spacecraft delivered six new lithium-ion batteries and adapter plates to replace aging nickel-hydrogen batteries used in two power channels on the space station’s port truss. Flight controllers already have robotically removed the batteries and adapter plates from HTV-7 and stored them on the space station’s truss. The batteries will be replaced through a series of robotic operations and spacewalks that will be scheduled at a later date.


Additional experiments and equipment delivered by HTV include a new sample holder for the Electrostatic Levitation Furnace (JAXA-ELF), a protein crystal growth experiment at low temperatures (JAXA LT PCG), an investigation that looks at the effect of microgravity on bone marrow (MARROW), a Life Sciences Glovebox, and additional EXPRESS Racks.


HTV-7 will re-enter the Earth’s atmosphere and burn up harmlessly over the South Pacific Ocean Nov. 10.


Related links:


Roscosmos statement: https://www.roscosmos.ru/25664/


Roscosmos: https://www.roscosmos.ru/


NASA: https://www.nasa.gov/


H-II Transfer Vehicle-7 (HTV-7): https://www.nasa.gov/feature/kounotori-htv-launches-arrivals-and-departures


JAXA-ELF: https://www.nasa.gov/mission_pages/station/research/experiments/1999.html


JAXA LT PCG: https://www.nasa.gov/mission_pages/station/research/experiments/2297.html


MARROW: https://www.nasa.gov/mission_pages/station/research/experiments/1931.html


Life Sciences Glovebox: https://www.nasa.gov/mission_pages/station/research/experiments/2723.html


EXPRESS Racks: https://www.nasa.gov/mission_pages/station/research/experiments/608.html


Expedition 57: https://www.nasa.gov/mission_pages/station/expeditions/expedition57/index.html


Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html


International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html


Images (mentioned), Text, Credits: NASA/Mark Garcia/Cheryl Warner/JSC/Dan Huot.


Best regards, Orbiter.chArchive link


Chasing a particle that is its own antiparticle


CERN – European Organization for Nuclear Research logo.


November 1, 2018


Neutrinos weigh almost nothing: you need at least 250 000 of them to outweigh a single electron. But what if their lightness could be explained by a mechanism that needs neutrinos to be their own antiparticles? The ATLAS collaboration at CERN is looking into this, using data from high-energy proton collisions collected at the Large Hadron Collider (LHC).


One way to explain neutrinos’ extreme lightness is the so-called seesaw mechanism, a popular extension of the Standard Model of particle physics. This mechanism involves pairing up the known light neutrinos with hypothetical heavy neutrinos. The heavier neutrino plays the part of a larger child on a seesaw, lifting the lighter neutrino to give it a small mass. But for this mechanism to work, both neutrinos need to be “Majorana” particles: particles that are indistinguishable from their antimatter counterparts.



The ATLAS experiment at CERN. (Image: Maximilien Brice/CERN)

Antimatter particles have the same mass as their corresponding matter particles but have the opposite electric charge. So, for example, an electron has a negative electric charge and its antiparticle, the positron, is positive. But neutrinos have no electric charge, opening up the possibility that they could be their own antiparticles. Finding heavy Majorana neutrinos could not only help explain neutrino mass, it could also lead to a better understanding of why matter is much more abundant in the universe than antimatter.


In an extended form of the seesaw model, these heavy Majorana neutrinos could potentially be light enough to be detected in LHC data. In a new paper, the ATLAS collaboration describes the results of its latest search for hints of these particles.


ATLAS looked for instances in which both a heavy Majorana neutrino and a “right-handed” W boson, another hypothetical particle, could appear. They used LHC data from collision events that produce two “jets” of particles plus a pair of energetic electrons or a pair of their heavier cousins, muons.


The researchers compared the observed number of such events with the number predicted by the Standard Model. They found no significant excess of events over the Standard Model expectation, indicating that no right-handed W bosons and heavy Majorana neutrinos took part in these collisions.



Large Hadron Collider (LHC). Animation Credit: CERN

However, the researchers were able to use their observations to excludepossible masses for these two particles. They excluded heavy Majorana neutrino masses up to about 3 TeV, for a right-handed W boson with a mass of 4.3 TeV. In addition, they explored for the first time the hypothesis that the Majorana neutrino is heavier than the right-handed W boson, placing a lower limit of 1.5 TeV on the mass of Majorana neutrinos. Further studies should be able to put tighter limits on the mass of heavy Majorana neutrinos in the hope of finding them – if, indeed, they exist.


Note:


CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.


The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.


Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.


Related links:


ATLAS collaboration paper: https://arxiv.org/pdf/1809.11105.pdf


ATLAS experiment: https://home.cern/about/experiments/atlas


Large Hadron Collider (LHC): https://home.cern/topics/large-hadron-collider


Standard Model: https://home.cern/about/physics/standard-model


Antimatter: https://home.cern/topics/antimatter


For more information about European Organization for Nuclear Research (CERN), Visit: https://home.cern/


Image (mentioned, Animation (mentioned), Text, Credits: CERN/Ana Lopes.


Best regards, Orbiter.chArchive link


HiPOD (1 November 2018): Gully Alcove in Lyot Crater   – Not a…




HiPOD (1 November 2018): Gully Alcove in Lyot Crater


   – Not a good place for Jawas to hide. Lyot is a large crater in the Vastitas Borealis region of Mars. (307 km above the surface. Black and white is less than 5 km across; enhanced color is less than 1 km.)


NASA/JPL/University of Arizona


A Caldera’s Steep SlopesThis image shows part of the steep wall…


A Caldera’s Steep Slopes


This image shows part of the steep wall of the caldera (a large volcanic crater) at the top of Ascraeus Mons, one of Mars’ giant volcanoes.


We can see chutes carved into the soft dust that has built up on the slope, with some similarities to gully landforms elsewhere on the planet. 


NASA/JPL/University of Arizona


Micro-earthquakes preceding a 4.2 earthquake near Istanbul as…


Micro-earthquakes preceding a 4.2 earthquake near Istanbul as early warning signs? http://www.geologypage.com/2018/11/micro-earthquakes-preceding-a-4-2-earthquake-near-istanbul-as-early-warning-signs.html


Caer Leb Romano-Celtic Settlement, Anglesey, North Wales, 20.10.18.The freshly mown grass...











Caer Leb Romano-Celtic Settlement, Anglesey, North Wales, 20.10.18.


The freshly mown grass made the earthworks of this defensive settlement more visible than usual.


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