вторник, 16 июля 2019 г.

Gaia starts mapping our galaxy’s bar


ESA — Gaia Mission patch.


16 July 2019


The first direct measurement of the bar-shaped collection of stars at the centre of our Milky Way galaxy has been made by combining data from ESA’s Gaia mission with complementary observations from ground- and space-based telescopes.


The second release of data from ESA’s Gaia star-mapping satellite, published in 2018, has been revolutionising many fields of astronomy. The unprecedented catalogue contains the brightnesses, positions, distance indicators and motions across the sky for more than one billion stars in our Milky Way galaxy, along with information about other celestial bodies.



Revealing the galactic bar

As impressive as this dataset sounds, this is really just the beginning. While the second release is based on the first 22 months of Gaia’s surveys, the satellite has been scanning the sky for five years and has many years ahead. New data releases planned in coming years will steadily improve measurements as well as provide extra information that will enable us to chart our home galaxy and delve into its history like never before.


Meanwhile, a team of astronomers have combined the latest Gaia data with infrared and optical observations performed from ground and space to provide a preview of what future releases of ESA’s stellar surveyor will reveal.


“We looked in particular at two of the stellar parameters contained in the Gaia data: the surface temperature of stars and the ‘extinction’, which is basically a measure of how much dust there is between us and the stars, obscuring their light and making it appear redder,” says Friedrich Anders from University of Barcelona, Spain, lead author of the new study.


“These two parameters are interconnected, but we can estimate them independently by adding extra information obtained by peering through the dust with infrared observations.”


The team combined the second Gaia data release with several infrared surveys using a computer code called StarHorse, developed by co-author Anna Queiroz and collaborators. The code compares the observations with stellar models to determine the surface temperature of stars, the extinction and an improved estimate of the distance to the stars.


As a result, the astronomers obtained much better determination of the distances to about 150 million stars – in some cases, the improvement is up to 20% or more. This enabled them to trace the distribution of stars across the Milky Way to much greater distances than possible with the original Gaia data alone.



Revealing the galactic bar

“With the second Gaia data release, we could probe a radius around the Sun of about 6500 light years, but with our new catalogue, we can extend this ‘Gaia sphere’ by three or four times, reaching out to the centre of the Milky Way,” explains co-author Cristina Chiappini from Leibniz Institute for Astrophysics Potsdam, Germany, where the project was coordinated.


There, at the centre of our galaxy, the data clearly reveals a large, elongated feature in the three-dimensional distribution of stars: the galactic bar.


“We know the Milky Way has a bar, like other barred spiral galaxies, but so far we only had indirect indications from the motions of stars and gas, or from star counts in infrared surveys. This is the first time that we see the galactic bar in 3D space, based on geometric measurements of stellar distances,” says Friedrich.


“Ultimately, we are interested in galactic archaeology: we want to reconstruct how the Milky Way formed and evolved, and to do so we have to understand the history of each and every one of its components,” adds Cristina.


“It is still unclear how the bar – a large amount of stars and gas rotating rigidly around the centre of the galaxy – formed, but with Gaia and other upcoming surveys in the next years we are certainly on the right path to figure it out.”


The team is looking forward to the next data release from the Apache Point Observatory Galaxy Evolution Experiment (APOGEE-2), as well as upcoming facilities such as the 4-metre Multi-Object Survey Telescope (4MOST) at the European Southern Observatory in Chile and the WEAVE (WHT Enhanced Area Velocity Explorer) survey at the William Herschel Telescope (WHT) in La Palma, Canary Islands.



Gaia

The third Gaia data release, currently planned for 2021, will include greatly improved distance determinations for a much larger number of stars, and is expected to enable progress in our understanding of the complex region at the centre of the Milky Way.


“With this study, we can enjoy a taster of the improvements in our knowledge of the Milky Way that can be expected from Gaia measurements in the third data release,” explains co-author Anthony Brown of Leiden University, The Netherlands, and chair of the Gaia Data Processing and Analysis Consortium Executive.


“We are revealing features in the Milky Way that we could not see otherwise: this is the power of Gaia, which is enhanced even further in combination with complementary surveys,” concludes Timo Prusti, Gaia project scientist at ESA.


Notes for editors:


“Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G=18” by F. Anders et al. is published in Astronomy & Astrophysics:
https://doi.org/10.1051/0004-6361/201935765


The study combines data from Gaia’s second release with the Pan-STARRS1 survey conducted with the first Pan-STARRS telescope in Hawaii, US; the Two Micron All Sky Survey (2MASS) conducted with telescopes in the US and Chile; the AllWISE survey from NASA’s Wide-field Infrared Survey Explorer (WISE).


The computations were conducted at the cluster facility of the Leibniz Institute for Astrophysics Potsdam, Germany.


The new catalogue is available here: https://data.aip.de/projects/starhorse2019.html


Gaia: http://www.esa.int/Our_Activities/Space_Science/Gaia


Text Credits: ESA/Timo Prusti/Leiden Observatory, Leiden University/Anthony Brown/Leibniz-Institut für Astrophysik Potsdam (AIP)/Cristina Chiappini/Institut de Ciències del Cosmos, Universitat de Barcelona/Friedrich Anders/Image, Video, Credits: Data: ESA/Gaia/DPAC, A. Khalatyan(AIP) & StarHorse team; Galaxy map: NASA/JPL-Caltech/R. Hurt (SSC/Caltech).


Best regards, Orbiter.ch Archive link


Remember the Women Who Made #Apollo50th Possible

As the world celebrates the 50th anniversary of the historic Moon landing, we remember some of the women whose hard work and ingenuity made it possible. The women featured here represent just a small fraction of the enormous contributions made by women during the Apollo era. 


Margaret Hamilton, Computer Programmer


image

Margaret Hamilton led the team that developed the building blocks of software engineering — a term that she coined herself. Her systems approach to the Apollo software development and insistence on rigorous testing was critical to the success of Apollo. In fact, the Apollo guidance software was so robust that no software bugs were found on any crewed Apollo missions, and it was adapted for use in Skylab, the Space Shuttle and the first digital fly-by-wire systems in aircraft.


In this photo, Hamilton stands next to a stack of Apollo Guidance Computer source code. As she noted, “There was no second chance. We all knew that.”


Katherine Johnson, Aerospace Technologist


image

As a very young girl, Katherine Johnson loved to count things. She counted everything, from the number of steps she took to get to the road to the number of forks and plates she washed when doing the dishes.


As an adult, Johnson became a “human computer” for the National Advisory Committee for Aeronautics, which in 1958, became NASA. Her calculations were crucial to syncing Apollo’s Lunar Lander with the Moon-orbiting Command and Service Module. “I went to work every day for 33 years happy. Never did I get up and say I don’t want to go to work.“


Judy Sullivan, Biomedical Engineer


image

This fabulous flip belongs to biomedical engineer Judy Sullivan, who monitored the vital signs of the Apollo 11 astronauts throughout their spaceflight training via small sensors attached to their bodies. On July 16, 1969, she was the only woman in the suit lab as the team helped Neil Armstrong suit up for launch.


Sullivan appeared on the game show “To Tell the Truth,” in which a celebrity panel had to guess which of the female contestants was a biomedical engineer. Her choice to wear a short, ruffled skirt stumped everyone and won her a $500 prize. In this photo, Sullivan monitors a console during a training exercise for the first lunar landing mission.


Billie Robertson, Mathematician


image

Billie Robertson, pictured here in 1972 running a real-time go-no-go simulation for the Apollo 17 mission, originally intended to become a math teacher. Instead, she worked with the Army Ballistic Missile Agency, which later became rolled into NASA. She created the manual for running computer models that were used to simulate launches for the Apollo, Skylab and Apollo Soyuz Test Project programs. 


Robertson regularly visited local schools over the course of her career, empowering young women to pursue careers in STEM and aerospace.


Mary Jackson, Aeronautical Engineer


image

In 1958, Mary Jackson became NASA’s first African-American female engineer. Her engineering specialty was the extremely complex field of boundary layer effects on aerospace vehicles at supersonic speeds.


In the 1970s, Jackson helped the students at Hampton’s King Street Community center build their own wind tunnel and use it to conduct experiments. “We have to do something like this to get them interested in science,” she said for the local newspaper. “Sometimes they are not aware of the number of black scientists, and don’t even know of the career opportunities until it is too late.”


Ethel Heinecke Bauer, Aerospace Engineer


image

After watching the launch of Sputnik in October 1957, Ethel Heinecke Bauer changed her major to mathematics. Over her 32 years at NASA, she worked at two different centers in mathematics, aerospace engineering, development and more. 


Bauer planned the lunar trajectories for the Apollo program including the ‘free return’ trajectory which allowed for a safe return in the event of a systems failure  — a trajectory used on Apollo 13, as well as the first three Apollo flights to the Moon. In the above photo, Bauer works on trajectories with the help of an orbital model.


Follow Women@NASA for more stories like this one, and make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.


2019 July 16 Apollo 11 Launches Humans to the Moon Video…


2019 July 16


Apollo 11 Launches Humans to the Moon
Video Credit: NASA


Explanation: Everybody saw the Moon. Nobody had ever been there. Humans across planet Earth watched in awe 50 years ago today as a powerful Saturn V rocket attempted to launch humans – to the Moon. Some in space flight guessed that the machinery was so complex, that so many things had to go right for it to work, that Apollo 11 would end up being another useful dress rehearsal for a later successful Moon-landing mission. But to the Moon they went. The featured video starts by showing astronauts Aldrin, Armstrong, and Collins making their way to the waiting rocket. As the large and mighty Saturn V launched, crowds watched from Cape Canaveral in Florida, USA and on television around the world. The events that unfolded over the next few days, including a dramatic moon walk 50 years ago this Saturday, will forever be remembered as a milestone in human history and an unrivaled demonstration of human ingenuity. This week, many places around the world are planning celebrations of the 50th anniversary of the first humans landing on the Moon.


∞ Source: apod.nasa.gov/apod/ap190716.html


The Poetry Path Photoset 1, Stenkrith Park, Kirkby Stephen, 14.7.19.

The Poetry Path Photoset 1, Stenkrith Park, Kirkby Stephen, 14.7.19.












Source link


ancientpeopleancientplaces: ‘A Prehistory’ PoemWritten by The…


ancientpeopleancientplaces:



‘A Prehistory’ Poem


Written by The Silicon Tribesman. All Rights Reserved, 2019



Source link


NASA’s Orbiting Carbon Observatory-3 Gets First Data


ISS — Orbiting Carbon Observatory-3 (OCO-3) logo.


July 15, 2019


NASA’s Orbiting Carbon Observatory-3 (OCO-3), the agency’s newest carbon dioxide-measuring mission to launch into space, has seen the light. From its perch on the International Space Station, OCO-3 captured its first glimpses of sunlight reflected by Earth’s surface on June 25, 2019. Just weeks later, the OCO-3 team was able to make its first determinations of carbon dioxide and solar-induced fluorescence — the «glow» that plants emit from photosynthesis, a process that includes the capture of carbon from the atmosphere.


The first image shows carbon dioxide, or CO2, over the United States during OCO-3’s first few days of science data collection. These initial measurements are consistent with measurements taken by OCO-3’s older sibling, OCO-2, over the same area — meaning that even though OCO-3’s instrument calibration is not yet complete, it is right on track to continue its (currently still operational) predecessor’s data record.



Image above: Preliminary carbon dioxide (CO2) measurements from OCO-3 over the United States. Image Credits: NASA/JPL-Caltech.


OCO-3 was also able to make its first measurements of solar-induced fluorescence. The second image shows solar-induced fluorescence in western Asia. Areas with lower plant glow — indicating lower photosynthesis activity — are shown in light green; areas with higher photosynthesis activity are shown in dark green. As expected, there is significant contrast in plant activity from areas of low vegetation near the Caspian Sea to the forests and farms north and east of the Mingachevir Reservoir (near the center of the image).


«The team is so excited to see how well OCO-3 is performing,» said Project Scientist Annmarie Eldering, who is based at NASA’s Jet Propulsion Laboratory in Pasadena, California. «These preliminary carbon dioxide and solar-induced fluorescence retrievals look fantastic and will only improve as calibration improves.»


OCO-3 launched to the space station on May 4. Although one of its main objectives is to continue the five-year data record started by OCO-2, it has two unique capabilities. First, OCO-3 is equipped with a new pointing mirror assembly that will allow scientists to map local variations in carbon dioxide from space more completely than can be achieved by OCO-2.


Second, the space station’s orbit will allow OCO-3 to see the same location on Earth at different times of day, which will allow scientists to study how carbon dioxide fluctuates throughout the day. OCO-2, not mounted on the space station, is in a near polar orbit that only allows it to see the same location at the same time of day.



International Space Station (ISS). Animation Credit: NASA

OCO-3’s data will complement data from two other Earth-observing missions aboard the space station — ECOSTRESS, which measures temperature stress and water use by plants, and GEDI, which assesses the amount of above-ground organic plant material present particularly in forests. The combined data from all of these instruments will give scientists both an unprecedented level of detail about how plants around the globe are responding to changes in climate and a more complete understanding of the carbon cycle.


The mission team expects to complete OCO-3’s in-orbit checkout phase — the period where they ensure all instruments and components are working and calibrated correctly — next month. They are scheduled to release official carbon dioxide and solar-induced fluorescence data to the science community a year later; however, given the quality of the measurements that OCO-3 is already making, the data will likely be available sooner.


The OCO-3 project is managed by JPL. Caltech manages JPL for NASA.


Related links:


OCO-3 (Orbiting Climate Observatory 3): https://www.nasa.gov/mission_pages/oco3/index.html


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


Image (mentioned), Animation (mentioned), Text, Credits: NASA/JPL/Esprit Smith.


Greetings, Orbiter.chArchive link


Gaia’s biggest operation since launch and commissioning


ESA — Gaia Mission patch.


15 July 2019


On Tuesday 16 July, teams at ESA’s mission control will perform an ‘orbit change manoeuvre’ on the Gaia space observatory – the biggest operation since the spacecraft was launched in 2013.



Gaia mapping the stars of the Milky Way

Gaia is on a mission to survey more than a billion stars, charting the largest three-dimensional map of our galaxy, the Milky Way. In so doing, the spacecraft is revealing the composition, formation and evolution of our galaxy, and a whole lot more.


For the last five and a half years, the spacecraft has travelled in an orbit designed to keep it out of Earth’s shadow, the second Lagrange point.



Spacecraft on L2

At 1.5 million km from Earth – four times further than the Moon – the ‘L2’ is a fabulous place from which to do science. As the Sun, Earth and Moon are all in one direction relative to the spacecraft, the rest of the sky is free to observe.


Placing Gaia in L2 has also ensured the star-catcher’s stability, because to this day it has never passed into Earth’s shadow. This has kept the spacecraft undisturbed by any change in temperature or varying infra-red radiation that would result from an Earth eclipse.


Although at the end of its planned lifetime, Gaia still has fuel in the tank and a lot more science to do, and so its mission continues. However, its eclipse-dodging path will not. In August and November of this year, without measures to change its orbit, the billion-star hunter will become partially shrouded by Earth’s shadow.



Avoiding Earth’s shadow

These two eclipses would prevent enough of the Sun’s light reaching Gaia’s solar panels that the observatory would shut down. As well as affecting its stability and power, such shade would cause a thermal disturbance, impacting the spacecraft’s scientific data acquisition for weeks.


Eclipse avoidance


To keep Gaia safe from these shady possibilities, operators at ESA’s mission control are planning the ‘Whitehead eclipse avoidance manoeuvre’.


On 16 July, Gaia will use a combination of its onboard thrusters to push it in a diagonal direction, away from the shadow, in a special technique known as ‘thrust vectoring’.


“We’ve named this operation after a great colleague of ours, Gary Whitehead, who sadly passed away last month after serving on the Flight Control Team for more than 11 years,” says David Milligan, Spacecraft Operations Manager for the mission. 



David Milligan leads the Gaia mission control team

“The manoeuvre will allow us to change Gaia’s orbit without having to turn the spacecraft body, keeping sunlight safely away from its extremely sensitive telescope.”


The world’s most stable space observatory


Gaia is an incredibly stable spacecraft. In fact, it is many, many times more stable – and therefore precise – than any other spacecraft in operation today.


“In space, stability takes time to establish,” explains David.


“Because any temperature change or unusual movement could take weeks to diminish or dampen, we always limit the time where special activities are performed that disturb scientific observations.”



Gaia, 2011, our galaxy as never seen before

“As well as the Whitehead manoeuvre, we will perform some maintenance and calibration activities on the spacecraft’s complex subsystems, which would otherwise have disturbed Gaia’s science.”


Because of its position and unparalleled precision, Gaia is one of the most productive spacecraft out there. Last year alone, more than 800 scientific papers were published based on its observations.



Gaia’s sky in colour

Related links:


ESA’s mission control: http://www.esa.int/About_Us/ESOC


Gaia space observatory: http://www.esa.int/Our_Activities/Space_Science/Gaia


Lagrange point: http://www.esa.int/Our_Activities/Operations/What_are_Lagrange_points


Flight Dynamics: http://www.esa.int/Our_Activities/Operations/gse/Flight_Dynamics


Images, Animation, Text, Credits: ESA/ATG medialab; background: ESO/S. Brunier/Gaia/DPAC, CC BY-SA 3.0 IGO.


Best regards, Orbiter.chArchive link


Crew and Cargo Rockets Poised for Rollout Ahead of Weekend Launches


ISS — Expedition 60 Mission patch.


July 15, 2019


Two rockets will be rolling out to their launch pads this week in Kazakhstan and Florida to blastoff to the International Space Station. The orbiting Expedition 60 trio will be welcoming three new crewmates Saturday and receive more science experiments and crew supplies next Tuesday, July 23.


First-time space flyer Andrew Morgan of NASA is joining veteran station residents Luca Parmitano of the European Space Agency and Alexander Skvortsov of Roscosmos for a ride to the station on Saturday. They will launch aboard the Soyuz MS-13 spacecraft from the Baikonur Cosmodrome at 12:28 p.m. EDT for a six-and-a-half hour trip to their new home in space. Their mission comes 50 years to the day Neil Armstrong and Buzz Aldrin first stepped on the Moon.



Image above: New Expedition 60 crewmembers (from left) Drew Morgan, Alexander Skvortsov and Luca Parmitano pose for pictures July 12 at the Cosmonaut Hotel crew quarters in Baikonur, Kazakhstan. Image Credits: Andrey Shelepin/GCTC.


The SpaceX Dragon space freighter is launching from Kennedy Space Center at 7:35 p.m. on Sunday for its 18th contracted mission to resupply the orbiting lab. The reusable cargo craft is delivering a variety of research gear supporting future space missions and healthier humans. NASA TV is broadcasting live the launch and arrival of both missions to the station.



International Space Station (ISS). Animation Credit: NASA

Flight Engineers Nick Hague and Christina Koch continue training today for the robotic capture of Dragon when it arrives early next Tuesday. Hague will command the Canadarm2 to reach out and grapple Dragon around 7 a.m. while Koch backs him up. Morgan will monitor telemetry during the spacecraft’s approach and rendezvous.


Station Commander Alexey Ovchinin spent the day on cleaning and maintenance duties on the Russian side of the space station. The veteran cosmonaut also inventoried medical equipment, medicines and dentistry gear.


Related article:


Science Soars to the Space Station on SpaceX CRS-18
https://orbiterchspacenews.blogspot.com/2019/07/science-soars-to-space-station-on.html


Related links:


Expedition 60: https://www.nasa.gov/mission_pages/station/expeditions/expedition60/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


Image (mentioned), Text, Credits: NASA/Mark Garcia.


Best regards, Orbiter.chArchive link


Delighted to announce a one month solo exhibition at The Senhouse Roman Museum in...

Delighted to announce a one month solo exhibition at The Senhouse Roman Museum in Maryport in the lovely Lake District in September through to October 2019. Hope you can join me!



Source link


Featured

    Солнечное затмение 14 декабря 2020 года  — полное  солнечное затмение  142  сароса , которое лучше всего будет видно в юго-восточной час...

Popular