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Titan in front of Saturn as seen by Cassini. (Image credit: NASA). VOA

Saturn’s moon Titan has all the right ingredients for life. NASA’s newly announced mission, Dragonfly, will explore the icy moon from the air and the ground to determine whether life ever arose there.

A familiar alien landscape

At first glance, Titan looks a lot like Earth. Lakes and seas are scattered across the northern hemisphere, and occasional rains dampen its sandy surface. The similarities end there – Titan is so cold that water exists as rock-hard ice, and oily methane falls from the sky and trickles into the seas. The sand is made up of organic materials built from carbon, hydrogen, nitrogen and oxygen, completely unlike what you’d find on any beach on Earth.

“One of the things I think is so exciting about Titan is how it can be alien and familiar at the same time. It’s 94 K [-290°F/-179°C] – it’s totally different material than what we’re used to interacting with on a daily basis: water-ice bedrock and liquid methane reservoirs and organic sand dunes,” said Elizabeth Turtle, Dragonfly’s principal investigator.

Artist’s rendering of Dragonfly in flight over Titan. (Image credit: Johns Hopkins APL). VOA

Titan’s surface is hidden from view by its hazy atmosphere, which is four times denser than Earth’s. Combined with the low gravity – just one-seventh as strong as what we’re used to – the thick atmosphere makes Titan an ideal target for an airborne explorer.

The idea of building an aircraft to fly in Titan’s thick atmosphere isn’t new, but it wasn’t until drone technology became more advanced that the Dragonfly team realized they could make their dream of flying on Titan a reality.

Leapfrogging across Titan

With its two sets of four propellers stacked on top of one another, Dragonfly looks a little bit like a drone, but it’s much bigger than something you would fly around in your backyard – around 3 meters long and more than a meter tall. The design will allow Dragonfly to take pictures from the air and land on Titan’s frozen surface for a closer view.

It will initially target a region near the moon’s equator that is covered in sand dunes, similar to what is found in deserts on Earth. From there, it will begin to explore the moon in a “leapfrog” way, scouting beyond its next target to see what lies ahead, then flying back to its planned landing site to touch down and analyze samples of the surface, snap photographs and scan for earthquakes – or titanquakes, rather.

Representative-color image of Titan’s surface. (Image credit: NASA). VOA

Traveling eight kilometers per leap, Dragonfly will make its way toward Selk crater, over 100 kilometers away. Scientists think that the heat from the collision that formed the crater would have liquefied the water ice in Titan’s crust, creating an environment with all the necessary components for life. The Dragonfly team hopes to learn whether combining organic material with liquid water and energy in the form of heat could have caused complex molecules to develop – or even life itself.

“We have this chance to explore a world that we know has all the ingredients for life, but how far did it get towards life?” said Melissa Trainer, deputy principal investigator for the mission.

Looking for life

If life has arisen on Titan, Dragonfly should be able to detect it. One thing its instruments will be on the lookout for is a class of molecules called amino acids, which are found in all life on Earth. Amino acids come in left- and right-handed varieties, just like a pair of gloves. When scientists make amino acids in a lab, they tend to form both kinds in equal amounts. Life, however, seems to prefer the left-handed kind. If amino acids are present on Titan, Dragonfly should be able to tell if there are unequal amounts of left- and right-handed varieties – a sign that life is present on the frozen surface.

Radar image of sand dunes in the Shangri-La region of Titan, where Dragonfly will land. (Image credit: NASA). VOA

Dragonfly will launch in 2026 and arrive at Titan in 2034 after an eight-year interplanetary cruise. The science and engineering teams have plenty to do in the meantime. “We have to finish designing and building a spacecraft, we have to test a bunch of instruments and get them calibrated,” said science team member Sarah Hörst. “There’s a lot of work to do … I can’t wait to get started!”

ALSO READ: NASA Selects Eight New Teams to Conduct Research about Moon

It’s a long way off, but the team is confident that the mission will be worth the wait and is excited to share what they learn with the public. “We want everyone to be able to come along on the journey to explore Titan,” Turtle said. (VOA)



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If humanity is hurt, God is hurt.

Religion without compassion might give way to hatred. Compassion with a "self-interest" motive is completely irreligious. But of late, some of the religions have departed from those basic human values. Love and compassion are for only those who follow their "specific" faith. Very sadly, the religions are up as trading commodities in the world of proselytization. Better preachers attract more followers. Of course, no issue if they are not vying for their religious "supremacy". But the ground reality is utterly different. The claim for exclusive supremacy has become the first commandment --- a real bone of contention among the existing religions. In the name of religion, we have polluted our minds. we have corrupted our souls. We have also gone so much astray that God must have now shut his gateway to heaven!

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Milky Way galaxy as seen from Chitkul Valley

NASA's Chandra X-ray Observatory has for the first time spotted signs of a planet transiting a star outside of the Milky Way galaxy, opening up a new avenue to search for exoplanets at greater distances than ever before.

The possible exoplanet -- or planets outside of our Solar System -- candidate is located in the spiral galaxy Messier 51 (M51), also called the Whirlpool Galaxy because of its distinctive profile, NASA said in a statement.

Astronomers have, so far, found all other known exoplanets and exoplanet candidates in the Milky Way galaxy, almost all of them less than about 3,000 light-years from Earth.

An exoplanet in M51 would be about 28 million light-years away, meaning it would be thousands of times farther away than those in the Milky Way, NASA said.

"We are trying to open up a whole new arena for finding other worlds by searching for planet candidates at X-ray wavelengths, a strategy that makes it possible to discover them in other galaxies," said Rosanne Di Stefano of the Center for Astrophysics at Harvard and Smithsonian (CfA) in Cambridge, Massachusetts, who led the study.

The findings are published in the journal Nature Astronomy.

The exoplanet candidate was spotted in a binary system called M51-ULS-1, located in M51. This binary system contains a black hole or neutron star orbiting a companion star with a mass about 20 times that of the Sun. The X-ray transit they found using Chandra data lasted about three hours, during which the X-ray emission decreased to zero.

Based on this and other information, the team estimates the exoplanet candidate in M51-ULS-1 would be roughly the size of Saturn and orbit the neutron star or black hole at about twice the distance of Saturn from the Sun.

The team looked for X-ray transits in three galaxies beyond the Milky Way galaxy, using both Chandra and the European Space Agency's XMM-Newton. Their search covered 55 systems in M51, 64 systems in Messier 101 (the "Pinwheel" galaxy), and 119 systems in Messier 104 (the "Sombrero" galaxy).

However, more data would be needed to verify the interpretation as an extragalactic exoplanet. One challenge is that the planet candidate's large orbit means it would not cross in front of its binary partner again for about 70 years, thwarting any attempts for a confirming observation for decades, NASA said.

Named in honor of the late Indian-American Nobel laureate, Subrahmanyan Chandrasekhar, the Chandra X-ray Observatory is the world's most powerful X-ray telescope. It has eight times greater resolution and is able to detect sources more than 20-times fainter than any previous X-ray telescope.

Known to the world as Chandra (which means "moon" or "luminous" in Sanskrit), Chandrasekhar was widely regarded as one of the foremost astrophysicists of the twentieth century. (IANS/JB)

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