Category: esa

Mars Express finds evidence of liquid water un…

A ground-penetrating radar aboard the European Space Agency’s Mars Express satellite has found evidence for a pool of liquid water, a potentially habitable environment, buried under layers of ice and dust at the red planet’s south pole.

“This subsurface anomaly on Mars has radar properties matching water or water-rich sediments,” said Roberto Orosei, principal investigator of the Mars Advanced Radar for Subsurface and Ionosphere Sounding instrument, or MARSIS, lead author of a paper in the journal Science describing the discovery.

The conclusion is based on observations of a relatively small area of Mars, but “it is an exciting prospect to think there could be more of these underground pockets of water elsewhere, yet to be discovered,” added Orosei.

Scientists have long theorised the presence of subsurface pools under the martian poles where the melting point of water could be decreased due to the weight of overlying layers of ice. The presence of salts in the Martian soil also would act to reduce the melting point and, perhaps, keep water liquid even at sub-freezing temperatures.

Earlier observations by MARSIS were inconclusive, but researchers developed new techniques to improve resolution and accuracy.

“We’d seen hints of interesting subsurface features for years but we couldn’t reproduce the result from orbit to orbit, because the sampling rates and resolution of our data was previously too low,” said Andrea Cicchetti, MARSIS operations manager.

“We had to come up with a new operating mode to bypass some onboard processing and trigger a higher sampling rate and thus improve the resolution of the footprint of our dataset. Now we see things that simply were not possible before.”

MARSIS works by firing penetrating radar beams at the surface of Mars and then measuring the strength of the signals as they are reflected back to the spacecraft.

The data indicating water came from a 200-kilometre-wide (124-mile-wide) area that shows the south polar region features multiple layers of ice and dust down to a depth of about 1.5 kilometres (0.9 miles). A particularly bright reflection below the layered deposits can be seen in a zone measuring about 20 kilometres (12 miles) across.

Orosei’s team interprets the bright reflection as the interface between overlying ice and a pool or pond of liquid water. The pool must be at least several centimetres thick for the MARSIS instrument to detect it.

“The long duration of Mars Express, and the exhausting effort made by the radar team to overcome many analytical challenges, enabled this much-awaited result, demonstrating that the mission and its payload still have a great science potential,” says Dmitri Titov, ESA’s Mars Express project scientist.

The discovery is significant because it raises the possibility, at least, of potentially habitable sub-surface environments.

“Some forms of microbial life are known to thrive in Earth’s subglacial environments, but could underground pockets of salty, sediment-rich liquid water on Mars also provide a suitable habitat, either now or in the past?” ESA asked in a statement. “Whether life has ever existed on Mars remains an open question.”

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Researchers came up with this theory using dat…

Researchers came up with this theory using data from both the New Horizons and Rosetta missions. Yay, science! You can read more about the comet theory here: https://www.space.com/40687-pluto-formation-1-billion-comets.html

Martian North Pole ESA / G. Neukum (Freie…

Martian North Pole

ESA / G. Neukum (Freie Universitaet, Berlin) / Bill Dunford

Cygnus Spacecraft Approaches Space Station i…

Cygnus Spacecraft Approaches Space Station in the Sunset

Image Credit: ESA/NASA

Centaurus A or NGC 5128 is a galaxy in the constellation of…

Centaurus A or NGC 5128 is a galaxy in the constellation of Centaurus.

The center of the galaxy contains a supermassive black hole with a mass equivalent to 55 million solar masses, which ejects a relativistic jet that is responsible for emissions in the X-ray and radio wavelengths. By taking radio observations of the jet separated by a decade, astronomers have determined that the inner parts of the jet are moving at about half of the speed of light. X-rays are produced farther out as the jet collides with surrounding gases resulting in the creation of highly energetic particles. The X-ray jets of Centaurus A are thousands of light-years long, while the radio jets are over a million light-years long

Image credit: ESO/ESA/NASA & Hubble   

ESA to Develop Gravitational Wave Space Mission with NASA…

ESA to Develop Gravitational Wave Space Mission with NASA Support

ESA (the European Space Agency) has selected the Laser Interferometer Space Antenna (LISA) for its third large-class mission in the agency’s Cosmic Vision science program. The three-spacecraft constellation is designed to study gravitational waves in space and is a concept long studied by both ESA and NASA.

ESA’s Science Program Committee announced the selection at a meeting on June 20. The mission will now be designed, budgeted and proposed for adoption before construction begins. LISA is expected to launch in 2034. NASA will be a partner with ESA in the design, development, operations and data analysis of the mission.

LISA consists of three spacecraft separated by 1.6 million miles (2.5 million kilometers) in a triangular formation that follows Earth in its orbit around the sun. Each spacecraft carries test masses that are shielded in such a way that the only force they respond to is gravity. Lasers measure the distances to test masses in all three spacecraft. Tiny changes in the lengths of each two-spacecraft arm signals the passage of gravitational waves through the formation.

Animation: ESA | NASA Goddard

Read more at: NASA

Four of Saturn’s Moons: Enceladus, Dione, Titan and…

Four of Saturn’s Moons: Enceladus, Dione, Titan and Mimas

Credit: NASA, ESA (STScI/AURA) by: Stuart Rankin

Sh2-106 is an emission nebula and a star formation region in…

Sh2-106 is an emission nebula and a star formation region in the constellation Cygnus.

Credit: NASA/ESA & Hubble

Baltic swirls by European Space Agency on Flickr.

Baltic swirls by European Space Agency on Flickr.