четверг, 14 ноября 2019 г.

Hayabusa2 departs from Ryugu

JAXA - Hayabusa2 Mission patch.

November 13, 2019

JAXA confirmed Hayabusa2, JAXA's asteroid explorer, left the target asteroid Ryugu.


On November 13, 2019, JAXA operated Hayabusa2 chemical propulsion thrusters for the spacecraft's orbit control.* The confirmation of the Hayabusa2 departure made at 10:05 a.m. (Japan Standard Time, JST) was based on the following data analyses;

· The thruster operation of Hayabusa2 occurred nominally
· The velocity leaving from Ryugu is approximately 9.2 cm/s
· The status of Hayabusa2 is normal

We are planning to conduct performance tests of onboard instruments, including the electric propulsion system, for the return to Earth.

(*) Hayabusa2 operation hours: 8:00 a.m. (JST) through 13:30 p.m. (JST), November 13. The thruster operation was pre-programmed in the event sequence earlier on the day, and the command was automatically executed.

Related Links:

Hayabusa2 Asteroid Probe (ISAS):

Asteroid Explorer "Hayabusa2":

Image, Text, Credits: Japan Aerospace Exploration Agency (JAXA)/National Research & Development Agency.

Greetings, Orbiter.ch

* This article was originally published here

Ancient 70-mile-long wall found in western Iran

Archaeologists have recently discovered the remains of a stone wall, which extends about 115 kilometres, in Sar Pol-e Zahab county, western Iran.

Ancient 70-mile-long wall found in western Iran
This satellite image was taken on July 31, 2019 by the WorldView-2 satellite. The red arrows show
 a surviving section of the Gawri Wall [Credit: © 2019 Maxar Technologies]
“With an estimated volume of approximately one million cubic metres of stone, it would have required significant resources in terms of workforce, materials and time,” wrote Sajjad Alibeigi, an assistant professor of Iranian Archaeology at Razi University in Kermanshah, Iran, in an article published online in the journal Antiquity.

The structure runs north-south from the Bamu Mountains in the north to an area near Zhaw Marg village in the south, Alibeigi wrote.

The archaeologist suggests that wall was built sometime between the fourth century BC and sixth century CE based on potteries found along the barrier.

Ancient 70-mile-long wall found in western Iran
Parts of a newly-discovered stone wall, which is stretched about 115 kilometres, in Sar Pol-e Zahab county,
western Iran [Credit: © 2019 Maxar Technologies]

“Remnants of structures, now destroyed, are visible in places along the wall. These may have been associated turrets or buildings,” Alibeigi cited, adding that the wall itself is made from “natural local materials, such as cobbles and boulders, with gypsum mortar surviving in places.”

Though the wall’s existence was unknown to archaeologists, those living near it have long known about the wall, calling it the “Gawri Wall,” Alibeigi wrote.

Archaeologists, however, are not certain who built the structure, and for what purpose. Because of the poor preservation of the barrier, the scientists aren’t even sure of its exact width and height. Their best estimates put it at 4 metres wide and about 3 metres high, he said.

Archaeologists have previously found similar structures in the north and northeastern parts of Iran which may have had a defensive purpose.

Source: Tehran Times [November 06, 2019]

* This article was originally published here

ESA’s Mars orbiters did not see latest Curiosity methane burst

ESA & ROSCOSMOS - ExoMars Mission patch.

November 13, 2019

In June, NASA’s Curiosity rover reported the highest burst of methane recorded yet, but neither ESA’s Mars Express nor the ExoMars Trace Gas Orbiter recorded any signs of the illusive gas, despite flying over the same location at a similar time.

Methane is of such fascination because on Earth a large proportion is generated by living things. It is known that methane has a lifetime of several hundred years before it is broken down by the Sun’s radiation, so the fact that it is detected on Mars suggests it has been released into the atmosphere recently – even if the gas itself was generated billions of years ago.

Key methane measurements at Mars

The methane mystery on Mars has had many twists and turns in recent years with unexpected detections and non-detections alike. Earlier this year it was reported that ESA’s Mars Express had detected a signature that matched one of Curiosity’s detections from within Gale Crater.

A recent spike by Curiosity, measured on 19 June 2019, and the highest yet at 21 ppbv, adds to the mystery because preliminary analysis suggest that Mars Express did not detect any on this occasion. (For comparison, the concentration of methane in Earth’s atmosphere is around 1800 ppbv, meaning that for every billion molecules in a given volume, 1800 are methane.)

The Mars Express measurements were taken in the martian daytime about five hours after Curiosity’s nighttime measurements; data collected by Mars Express over one day before also did not reveal any signatures. Meanwhile Curiosity’s readings had returned to background levels when further measurements were taken in the following days.

The Mars Express measurement technique allowing data to be inferred right down to the martian surface with its limit of detection around 2 ppbv.

How to create and destroy methane at Mars

The ESA-Roscosmos Trace Gas Orbiter (TGO), the most sensitive detector for trace gases at Mars, also did not detect any methane while flying nearby within a few days before and after Curiosity’s detection.

In general, TGO is capable of measuring at parts per trillion levels and accessing down to about 3 km altitude, but this can depend on how dusty the atmosphere is. When measurements were taken at low latitudes on 21 June 2019, the atmosphere was dusty and cloudy, resulting in measurements accessing 20-15 km above the surface with an upper limit of 0.07 ppbv.

The global lack of methane recorded by TGO is adding to the overall mystery, and corroborating the results of the different instruments is keeping all teams busy.

Ten things you did not know about Mars: 7. Methane

“Taking the results together suggests that the latest spike measured by Curiosity was very short lived – less than one martian day – and likely local,” says Marco Giuranna, principal investigator for the Planetary Fourier Spectrometer onboard Mars Express that is used to detect methane.

“Curiosity measured the methane at night, and if it was released at that time, we would expect it to have been trapped near the surface until sunrise before getting rapidly mixed and transported away. As a result, there would be no chance for it to be detected by Mars Express or TGO.

“By comparison, the spike we co-measured in 2013 must have been of a longer duration or more intense at its source – which we believe was outside Gale Crater – such that it could be detected by our instrument on Mars Express as well.”

The teams are continuing to look into the influence of atmospheric circulation between day and night, and if the location of Curiosity inside an impact crater plays a role. They are also studying the way that methane is destroyed, in case the gas is being absorbed by surface rocks again before it is circulated more widely into the atmosphere.

ESA-Roscosmos Trace Gas Orbiter (TGO)

“Combining observations from the surface and from orbit with future coordinated observations will help us understand the behaviour of methane in the atmosphere, with non-detections like that from TGO providing upper limits, constraints and important context,” adds Håkan Svedhem, ESA’s TGO project scientist.

The Curiosity measurements were made by the Sample Analysis at Mars tunable laser spectrometer, the Mars Express measurements were taken by the Planetary Fourier Spectrometer (PFS) and the TGO measurements were taken by the Atmospheric Chemistry Suite (ACS) and the Nadir and Occultation for Mars Discovery (NOMAD) instrument. The TGO results were presented at the International Conference on Mars in Pasadena, California in July and at the EPSC-DPS conference in Geneva in September. The full analysis of the Mars Express data is ongoing and will be reported formally at a later date.

Related article:

Curiosity Detects Unusually High Methane Levels

Related links:

ExoMars: http://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Exploration/ExoMars

Human and Robotic Exploration: http://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration

ESA/Håkan Svedhem/Dmitri Titov/Royal Belgian Institute for Space Aeronomy/Ann-Carine Vandaele/Space Research Institute, Russian Academy of Sciences/Oleg Korablev/Istituto Nazionale di Astrofisica – Istituto di Astrofisica e Planetologia Spaziali (INAF–IAPS)/Marco Giuranna/NASA.

Best regards, Orbiter.ch

* This article was originally published here

Ancient pottery fragment depicting female shaman found in Japan

A pottery fragment depicting a shaman with breasts has been found for the first time at a dig site here, shedding light on the religious role women played in ancient agriculture.

Ancient pottery fragment depicting female shaman found in Japan
An earthenware fragment showing a female shaman with arms extended
in a religious pose [Credit: Taku Hosokawa]
The figure on the artifact, dating to the first century BC, has her arms raised in what appears to be a pose to pray for bountiful harvests.

It was unearthed at the Shimizukaze archaeological site straddling Tawaramoto and Tenri in the prefecture, where burial-related and housing remains from the Yayoi Pottery Culture period (300 BC-AD 300) were also found.

While figures spreading or raising their arms appear on some of more than 40 earthenware paintings depicting a human from the Yayoi period found across Japan, the discovery is especially significant because it indicates that the individuals in such poses are invariably women.

Tawaramoto’s education board said that the earthenware piece measuring up to 16 centimeters wide and 12 cm long is believed to have been a section between the mouth and center of a large pot.

It was discovered at the former site of a river from the mid-Yayoi period when a 40-square-meter area was surveyed between May and June.

Ancient pottery fragment depicting female shaman found in Japan
Credit: Taku Hosokawa

The figure has wing-like sleeves, and the face has been illustrated with eyes, eyebrows, nose and mouth.

Spreading both arms is known as the “tamafuri” pose and is said to help revitalize and revive souls to pray for good harvests by giving vitality to rice plants.

Yoshiki Fukasawa, a visiting professor of archaeology at Tenri University, noted the possibility of the depicted woman having served as a shaman like noted Queen Himiko, who is mentioned in China’s “Gishi Wajinden” (Accounts of the Wa people, Records of Wei).

“The artifact was created 300 years earlier than the era of Himiko, who served as a priestess,” said Fukasawa. “The primary discovery shows that a tradition existed on the Japanese archipelago where women played a part in religious services, and that Himiko emerged against this historical background.”

Author: Takumi Okada | Source: The Asahi Shimbun [October 31, 2019]

* This article was originally published here

Name the Mars 2020 Rover!In 2020, we’re sending our newest robotic scientist to Mars, paving the way...

Name the Mars 2020 Rover!

In 2020, we’re sending our newest robotic scientist to Mars, paving the way for humans to one day live and work on the Red Planet. The only problem? Our Mars 2020 rover doesn’t have a name yet! We’re calling on K-12 students across the country to find the very best name for our next robotic space explorer!

The Mission

Before we can send astronauts to Mars we need to learn more about the planet and its climate. This is where the Mars 2020 rover comes in. Its job will be to explore the Red Planet in search of signs of ancient life! It will also be tasked with characterizing the planet’s climate and geology, and collecting samples from its surface. Because of the groundwork laid by rovers such as this, humans will one day become an interplanetary species!

Meet the rovers that came before it

The-soon-to-be-named rover will be joining the team of historic NASA robots that have been working away in space for the past 27 years! All of our robot explorers have their own missions, personality and names that help tell their own story. The most recent Mars rover, Curiosity, landed on the planet in 2012 and is responsible for finding evidence of a possible ancient oasis! Data Curiosity collected suggests salty, shallow ponds once dotted a Martian crater – a sign of the planet’s drying climate. Before Curiosity, robotic twins Spirit and Opportunity landed on Mars in 2004. Their instruments helped them search for evidence of liquid water that may have been present in the planet’s past!

Submit your entry today!

One grand prize winner will name the rover and be invited to Cape Canaveral, Florida to see the spacecraft launch in July 2020! So, what will it take to win? Just send us your proposed name and a short essay (no more than 150 words), explaining why the name you chose is the best for this very special robotic explorer! The deadline is November 1st, so get your thinking cap on and tell us your most creative idea! Apply here!

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

NASA's Solar Dynamics Observatory sent back images of the transit

NASA - Solar Dynamics Observatory (SDO) patch.

November 13, 2019

On November 11, 2019, SDO will watch the planet Mercury move across the face of the Sun.

2019 Mercury Transit by SDO

The transit views begin at 1200 UTC (7 am ET) and end at 1845 UTC (1:45 pm ET). Mercury will be visible in some of the AIA channels throughout the event.

Mercury will move onto the HMI images at 1241 UTC (7:41 am ET) and exit HMI at 1805 UTC (1:05 pm ET).