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Posts tagged ‘Cometris Star Archives’

Mars Express views moons set against Saturn’s rings

Paris (ESA)

Mar 02, 2018

New images and video from ESA’s Mars Express show Phobos and Deimos drifting in front of Saturn and background stars, revealing more about the positioning and surfaces of the Red Planet’s mysterious moons.

Mars’ two small moons are intriguing objects. While we know something of their size, appearance and position thanks to spacecraft such as ESA’s Mars Express, much remains unknown. How and where did they form? What are they made of? What exactly is on their surfaces – and could we send a lander to find out?

Mars Express has been studying Mars and its moons for many years. The satellite recently observed both Phobos, Mars’ innermost and largest moon at up to 26 km in diameter, and Deimos, Phobos’ smaller sibling at 6.2 km in diameter, to produce this new video and series of images.

The video combines 30 images as individual frames and shows Phobos passing through the frame with the gas giant planet Saturn, which sits roughly a billion kilometers away, visible as a small ringed dot in the background.

Precise positioning

Mars Express has been working for more than 14 years at the Red Planet. While several other spacecraft are currently at Mars, including ESA’s ExoMars Trace Gas Orbiter, Mars Express’ near-polar elliptical orbit gives it some advantages for certain observations.

In particular, its path takes it closer to Phobos than any other spacecraft, and allows it to periodically observe the moon close up from within 150 km – in the summer of 2017, it came as close as 115 km.

The images of Phobos and Saturn comprising the video were taken on 26 November 2016 by the High Resolution Stereo Camera. Mars Express was travelling at about 3 km/s when it obtained these views, highlighting the importance of knowing Phobos’ exact position: the spacecraft had just seconds to image the rocky body as it passed by.

Scientists repeatedly refine our knowledge of the moons’ positioning in the sky and ensure it is up-to-date by observing each moon against background reference stars and other Solar System bodies. These calculated positions are incredibly precise, and can be accurate to just a couple of kilometers.

Studying the surface

These images are also key to understanding the surface and structure of the moons. Alongside the view of Phobos set against Saturn, Mars Express also obtained images of Phobos against a reference star on 8 January 2018 (star circled in red), close-up images of Phobos’ pockmarked surface on 12 September 2017, and images of Deimos with Saturn on 15 January 2018.

The frames of Phobos’ surface were taken during close flybys, and show the bumpy, irregular and dimpled surface in detail. Phobos has one of the largest impact craters relative to body size in the Solar System: Stickney crater’s 9 km diameter is around a third of the moon’s diameter. It is visible as the largest crater in these frames.

The same side of the moon always faces the planet, which means multiple flybys are needed to build up a full map of its surface.

Deimos is visible as an irregular and partially shadowed body in the foreground of one of the new Mars Express images, with the delicate rings of Saturn just about visible encircling the small dot in the background.

Deimos is significantly further away from Mars than its bigger sibling: while Phobos sits at just 6000 km from the surface, Deimos orbits at nearly 23 500 km. For comparison, our own satellite is around 16 times further from Earth than Deimos is from Mars.

Future missions to Mars

There is much we still wish to know about the Mars system. The moons remain particularly mysterious, with open questions about their origins, formation and composition. As a result, combined with their proximity to the Red Planet, the little moons have generated a lot of interest as a target for future missions.

Phobos in particular has been considered for a possible landing and sample-return mission. Owing to its nearness to Mars and one side always facing its parent, the moon could also be a possible location for a more permanent observation post. This would enable long-term monitoring and study of the martian surface and atmosphere, and communications relay for other spacecraft.

Understanding more about the positioning, surface, composition and terrain of both Phobos and Deimos from Mars Express observations is important for preparing for future missions.

Source: Mars Daily.



NASA finds a large amount of water in an exoplanet’s atmosphere

by Ann Jenkins for STSI News

Baltimore MD (SPX)

Mar 02, 2018

Much like detectives study fingerprints to identify the culprit, scientists used NASA’s Hubble and Spitzer space telescopes to identify the “fingerprints” of water in the atmosphere of a hot, bloated, Saturn-mass exoplanet some 700 light-years away. And, they found a lot of water. In fact, the planet, known as WASP-39b, has three times as much water as Saturn does.

Though no planet like this resides in our solar system, WASP-39b can provide new insights into how and where planets form around a star, say researchers. This exoplanet is so unique, it underscores the fact that the more astronomers learn about the complexity of other worlds, the more there is to learn about their origins. This latest observation is a significant step toward characterizing these worlds.

Although the researchers predicted they’d see water, they were surprised by how much water they found in this “hot Saturn.” Because WASP-39b has so much more water than our famously ringed neighbor, it must have formed differently. The amount of water suggests that the planet actually developed far away from the star, where it was bombarded by a lot of icy material. WASP-39b likely had an interesting evolutionary history as it migrated in, taking an epic journey across its planetary system and perhaps obliterating planetary objects in its path.

“We need to look outward so we can understand our own solar system,” explained lead investigator Hannah Wakeford of the Space Telescope Science Institute in Baltimore, Maryland, and the University of Exeter in Devon, United Kingdom. “But exoplanets are showing us that planet formation is more complicated and more confusing than we thought it was. And that’s fantastic!”

Wakeford and her team were able to analyze the atmospheric components of this exoplanet, which is similar in mass to Saturn but profoundly different in many other ways. By dissecting starlight filtering through the planet’s atmosphere into its component colors, the team found clear evidence for water. This water is detected as vapor in the atmosphere.

Using Hubble and Spitzer, the team has captured the most complete spectrum of an exoplanet’s atmosphere possible with present-day technology. “This spectrum is thus far the most beautiful example we have of what a clear exoplanet atmosphere looks like,” said Wakeford.

“WASP-39b shows exoplanets can have much different compositions than those of our solar system,” said co-author David Sing of the University of Exeter in Devon, United Kingdom. “Hopefully this diversity we see in exoplanets will give us clues in figuring out all the different ways a planet can form and evolve.”

Located in the constellation Virgo, WASP-39b whips around a quiet, Sun-like star, called WASP-39, once every four days. The exoplanet is currently positioned more than 20 times closer to its star than Earth is to the Sun. It is tidally locked, meaning it always shows the same face to its star.

Its day-side temperature is a scorching 1,430 degrees Fahrenheit (776.7 degrees Celsius). Powerful winds transport heat from the day-side around the planet, keeping the permanent night-side almost as hot. Although it is called a “hot Saturn,” WASP-39b is not known to have rings. Instead, it has a puffy atmosphere that is free of high-altitude clouds, allowing Wakeford and her team to peer down into its depths.

Looking ahead, Wakeford hopes to use the James Webb Space Telescope – scheduled to launch in 2019 – to get an even more complete spectrum of the exoplanet. Webb will be able to give information about the planet’s atmospheric carbon, which absorbs light at longer, infrared wavelengths than Hubble can see. By understanding the amount of carbon and oxygen in the atmosphere, scientists can learn even more about where and how this planet formed.

Source: Space Daily.


At last minute, Russia scrubs cargo launch to space station

February 11, 2018

MOSCOW (AP) — Russia has scrubbed the planned launch of an unmanned cargo spacecraft that was to have delivered tons of supplies to the International Space Station. Preparations for the launch of the Progress ship from the Baikonur complex in Kazakhstan appeared to be proceeding smoothly Sunday until less than a minute before the liftoff.

Roscosmos, the Russian space agency, said the launch was halted after an automated command, but said the reason for the command was under investigation. It said the launch is rescheduled for Tuesday. The Russian spacecraft carry fuel, food and other supplies to the ISS. This one was to have attempted a new fast route to the station, docking just 3.5 hours after launch after just two Earth orbits.

There are six astronauts currently aboard the ISS — two Russians, three Americans and one from Japan.

Royal audience as SpaceX launches satellite for Luxembourg

February 01, 2018

CAPE CANAVERAL, Fla. (AP) — SpaceX had a royal audience as it launched a satellite for Luxembourg. The Falcon 9 rocket blasted off late Wednesday afternoon from Cape Canaveral, Florida, hoisting GovSat-1 for the government of Luxembourg and SES, the European country’s prime satellite operator. The satellite will support both military and civilian security efforts.

Witnessing the launch were Luxembourg’s Prince Guillaume and his wife, Stephanie. The country’s prime minister, Xavier Bettel, and other high-ranking officials also were present. The rocket’s first-stage booster — which also flew last spring — was not recovered this time. Instead, it dropped into the Atlantic.

With GovSat-1 now in orbit, SpaceX can focus on next week’s debut of its new, big Falcon Heavy rocket. The test flight is scheduled for Tuesday.

Russia at work on new station, lunar trips: says top rocket scientist

Moscow (Sputnik)

Jan 24, 2018

Russia is set to spend the next decade working on a potential new station that might be built if the International Space Station (ISS) project is terminated, as well as a spacecraft capable of making trips to the Moon, General Designer of Russia’s Manned Programs Yevgeny Mikrin said Tuesday.

The ISS participants have agreed to maintain the program until 2024, but it is unclear what will happen afterward. In April last year, Igor Komarov, director general of the Russian national space agency, Roscosmos, said the Russian side was open to extending the program until 2028. However, no final decision has been made on the future of the project. The participants include Russian, US, Japanese, European and Canadian space agencies.

“If the decision is made to stop the work of the ISS, a Russian station may be set up… It is planned to include five modules,” Mikrin said at the Academic Space Conference in Moscow.

The station would be able to house a crew of three and it would weigh about 60 tonnes, that is, almost seven times less than the ISS.

For the time being, however, Russia is planning to finish the second phase of the construction of the Russian segment of the ISS and add three new modules to it. The modules are designed in a way that would allow them to become the basis for a new independent station.

A new cargo spacecraft with larger payload capacity that is being designed at Russia’s Rocket and Space Corporation Energia may be used to deliver supplies to the new station.


The flight and docking of the Federation manned spacecraft to the ISS, planned for 2024, is among the plans for the existing program, however, the Federation will be capable of a wide range of operations, including travel to the Moon.

The spacecraft, according to Mikrin, will be able to land on the surface of the Moon with a precision of 4.3 miles.

“The advantages of the new spacecraft is the possibility of multiple use of the landing section, up to 10 times, soft landing on a special landing device, the increase of the landing precision up to seven kilometers, ensuring the crew safety throughout the launch phase and increased comfort,” Mikrin explained.

The Federation can carry a crew of four and is intended for transporting cargo and people to the orbital station and to the Moon. The designer said that the Moon program is expected to culminate in the establishment of a Moon base, where it will be possible to mine for rare and precious resources, among other things.

The Federation spacecraft is capable of being in an autonomous flight for up to 30 days and a part of an orbital station for up to a year.

The first Federation is expected to be built by 2021.

Off to Moon With RD-150

The new hydrogen engine for the upper part of the super heavy-lift launch vehicle will be named RD-150, according to the designer.

The third-stage launcher will be designed based on RD-120 made for Buran project, a reusable spacecraft program that began in the 1970s.

Mikrin added that the first two stages would be designed based on the first stages of the Soyuz-5 rocket, currently under development.

The super heavy-lift launch vehicle is expected to be first used in 2023-2035 to deliver the Federation spacecraft to the Moon’s polar orbit.

Source: Moon Daily.


TRAPPIST-1 System Planets Potentially Habitable

Tucson AZ (SPX)

Jan 24, 2018

Two exoplanets in the TRAPPIST-1 system have been identified as most likely to be habitable, a paper by PSI Senior Scientist Amy Barr says.

The TRAPPIST-1 system has been of great interest to observers and planetary scientists because it seems to contain seven planets that are all roughly Earth-sized, Barr and co-authors Vera Dobos and Laszlo L. Kiss said in “Interior Structures and Tidal Heating in the TRAPPIST-1 Planets” that appears in Astronomy and Astrophysics.

“Because the TRAPPIST-1 star is very old and dim, the surfaces of the planets have relatively cool temperatures by planetary standards, ranging from 400 degrees Kelvin (260 degrees Fahrenheit), which is cooler than Venus, to 167 degrees Kelvin (-159 degrees Fahrenheit), which is colder than Earth’s poles,” Barr said.

“The planets also orbit very close to the star, with orbital periods of a few days. Because their orbits are eccentric – not quite circular – these planets could experience tidal heating just like the moons of Jupiter and Saturn.”

“Assuming the planets are composed of water ice, rock, and iron, we determine how much of each might be present, and how thick the different layers would be. Because the masses and radii of the planets are not very well-constrained, we show the full range of possible interior structures and interior compositions.” Barr said. The team’s results show that improved estimates of the masses of each planet can help determine whether each of the planets has a significant amount of water.

The planets studied are referred to by letter, planets b through h, in order of their distance from the star. Analyses performed by co-author Vera Dobos show that planets d and e are the most likely to be habitable due to their moderate surface temperatures, modest amounts of tidal heating, and because their heat fluxes are low enough to avoid entering a runaway greenhouse state. A global water ocean likely covers planet d.

The team calculated the balance between tidal heating and heat transport by convection in the mantles of each planet. Results show that planets b and c likely have partially molten rock mantles. The paper also shows that planet c likely has a solid rock surface, and could have eruptions of silicate magmas on its surface driven by tidal heating, similar to Jupiter’s moon Io.

Source: Space Daily.


Russian experts looking into nation’s recent space failures

December 28, 2017

MOSCOW (AP) — The Kremlin says authorities are looking into recent failures in Russia’s space industry. In the most embarrassing incident in recent months, a satellite launched from Russia’s new Launchpad was lost due to a programming error.

Deputy Prime Minister Dmitry Rogozin said Wednesday that the Meteor-M weather satellite, which was launched Nov. 28 from the new Vostochny cosmodrome in Russia’s Far East, was lost because it was programmed with the bearings for takeoff from Baikonur, Russia’s main launch pad that it leases in Kazakhstan.

The loss of the satellite and the corruption scandals around the construction of Vostochny have put pressure on Rogozin, who oversees the space industry. Asked about a possible overhaul of Russia’s space industry, Kremlin spokesman Dmitry Peskov said Thursday that officials are looking into the situation.

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