cosmos

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On the broad Martian equatorial plain called Elysium Planitia, a huge swath of dark material has been hiding a secret, one that could upend our beliefs about the recent history of Mars.

In research published in April in Icarus a team led by David Horvath of the Planetary Science Institute used Mars Reconnaissance Orbiter (MRO) images to study rocky debris in the Cerberus Fossae fissures, finding evidence of volcanism on Mars — and what’s more, the Martian eruption happened so recently that ancient humans were already roaming the Earth.

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Voyager 1, having spent over 43 years zooming away from Earth since its 1977 launch, is now a very long way away indeed.

Its distance from the Sun is over 150 times the distance between Earth and the Sun. It takes over 21 hours for transmissions traveling at light speed to arrive at Earth. It officially passed the heliopause - the boundary at which pressure from the solar wind is no longer sufficient to push into the wind from interstellar space - in 2012.

Voyager 1 has left the Solar System - and it's finding that the void of space is not quite so void-like, after all.

In the latest analysis of data from the intrepid probe, from a distance of nearly 23 billion kilometers (over 14 billion miles), astronomers have discovered, from 2017 onwards, a constant hum from plasma waves in the interstellar medium, the diffuse gas that lurks between the stars.

"It's very faint and monotone, because it is in a narrow frequency bandwidth," said astronomer Stella Koch Ocker of Cornell University. "We're detecting the faint, persistent hum of interstellar gas."

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Our telescopes on Earth and in space may one day welcome a new companion: a massive telescope on the moon. What's extra clever about the Lunar Crater Radio Telescope idea is that the LCRT would use an existing crater on the moon's far side.

On Wednesday, the Jet Propulsion Laboratory announced the LCRT is receiving $500,000 in Phase II funding through NASA's Innovative Advanced Concepts program. While the LCRT isn't an official NASA mission yet, the funding round is a vote of confidence in the idea.

Last year, the LCRT earned $125,000 in Phase I funding to explore the concept of sending robots to the moon's far side to build a telescope out of wire mesh suspended in a crater. The moon is a tempting place to locate a telescope because it could shield the device from Earth's radio signals and it wouldn't have to contend with an atmosphere.

"The LCRT's primary objective would be to measure the long-wavelength radio waves generated by the cosmic Dark Ages -- a period that lasted for a few hundred million years after the Big Bang, but before the first stars blinked into existence," JPL said in a statement.

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A team of international scientists, led by the Galician Institute of High Energy Physics (IGFAE) and the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav), has proposed a simple and novel method to bring the accuracy of the Hubble constant measurements down to 2% using a single observation of a pair of merging neutron stars.

The universe is in continuous expansion. Because of this, distant objects such as galaxies are moving away from us. In fact, the further away they are, the faster they move. Scientists describe this expansion through a famous number known as the Hubble constant, which tells us how fast objects in the universe recede from us depending on their distance to us. By measuring the Hubble constant in a precise way, we can also determine some of the most fundamental properties of the universe, including its age.

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The Hubble Space Telescope has peered out into the cosmos and spotted its youngest exoplanet yet, a giant world 379 light-years from Earth that's still growing.

Planets form as dust and gas, swirling around in a circumstellar disk surrounding their star, collides and condenses to slowly become a "ball." Far out in the constellation Centaurus, Hubble has spotted a planet still coming together. The young gas giant exoplanet, designated PDS 70b, is "just" 5 million years old, Hubble scientists said. While the planet is still gathering mass, pulling it from the young star it orbits, it's already huge — roughly the size of Jupiter.

In a new study, scientists took advantage of this unique opportunity to study a planet in its formative years like PDS 70b with Hubble's telescope eye.

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One of the great mysteries of modern space science is neatly summed up by the view from NASA's Perseverance, which just landed on Mars: Today it's a desert planet, and yet the rover is sitting right next to an ancient river delta.

The apparent contradiction has puzzled scientists for decades, especially because at the same time that Mars had flowing rivers, it was getting less than a third as much sunshine as we enjoy today on Earth.

But a new study led by University of Chicago planetary scientist Kite, an assistant professor of geophysical sciences and an expert on climates of other worlds, uses a computer model to put forth a promising explanation: Mars could have had a thin layer of icy, high-altitude clouds that caused a greenhouse effect.

"There's been an embarrassing disconnect between our evidence, and our ability to explain it in terms of physics and chemistry," said Kite. "This hypothesis goes a long way toward closing that gap."

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In recent years there has been an exhaustive study of red dwarf stars to find exoplanets in orbit around them. These stars have effective surface temperatures between 2400 and 3700 K (over 2000 degrees cooler than the Sun), and masses between 0.08 and 0.45 solar masses. In this context, a team of researchers led by Borja Toledo Padrón, a Severo Ochoa-La Caixa doctoral student at the Instituto de Astrofísica de Canarias (IAC), specializing in the search for planets around this type of stars, has discovered a super-Earth orbiting the star GJ 740, a red dwarf star situated some 36 light years from the Earth.

The planet orbits its star with a period of 2.4 days and its mass is around 3 times the mass of the Earth. Because the star is so close to the Sun, and the planet so close to the star, this new super-Earth could be the object of future researches with very large diameter telescopes towards the end of this decade. The results of the study were recently published in the journal Astronomy & Astrophysics.

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NASA has chosen SpaceX to build spacecraft that will take humans to the Moon for the first time since the Apollo program wrapped up in 1972 — first reported by The Washington Post. The agency announced SpaceX had won the contract for the Artemis lunar lander at a press conference this afternoon. The company beat out Blue Origin (which teamed up with key aerospace players like Lockheed Martin) and defense contractor Dynetics to win the $2.9 billion contract. It was previously expected that NASA would select two of the companies.

NASA tends to pick multiple contractors for its key programs to promote competition and to ensure there are several options in case a provider can't make good on its proposal. It chose all three for the initial step of the contract last year but it has decided to go all in on SpaceX.

The company pitched its Starship for the Artemis missions. Although SpaceX has been encountering problems with the reusable spacecraft during testing (all of the prototypes have crashed and/or exploded thus far), NASA seems confident the company can get it right. SpaceX is still planning to take Starship into orbit later this year. The agency also explained that the reusable nature of the Starship factored into its decision.

The contract is a major victory for SpaceX. It's already working with NASA to ferry astronauts to and from the International Space Station, with the next mission scheduled for April 22nd.

When the Artemis program spun up under the Trump administration, the goal was to take astronauts back to the Moon in 2024, but the timeline for the project is under review. NASA doesn't currently have the funding it needs to make the mission happen by 2024 either.

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In fascinating new research, cosmologists explain the history of the universe as one of self-teaching, autodidactic algorithms.

The scientists, including physicists from Brown University and the Flatiron Institute, say the universe has probed all the possible physical laws before landing on the ones we observe around us today. Could this wild idea help inform scientific research to come?

In their novella-length paper, published to the pre-print server arXiV, the researchers—who received “computational, logistical, and other general support” from Microsoft—offer ideas “at the intersection of theoretical physics, computer science, and philosophy of science with a discussion from all three perspectives,” they write, teasing the bigness and multidisciplinary nature of the research.

Here’s how it works: Our universe observes a whole bunch of laws of physics, but the researchers say other possible laws of physics seem equally likely, given the way mathematics works in the universe. So if a group of candidate laws were equally likely, then how did we end up with the laws we really have?

“The notion of ‘learning’ as we use it is more than moment-to-moment, brute adaptation. It is a cumulative process that can be thought of as theorizing, modeling, and predicting. For instance, the DNA/RNA/protein system on Earth must have arisen from an adaptive process, and yet it foresees a space of organisms much larger than could be called upon in any given moment of adaptation.”

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Something’s fishy in the southern constellation Phoenix.

Strange radio emissions from a distant galaxy cluster take the shape of a gigantic jellyfish, complete with head and tentacles. Moreover, the cosmic jellyfish emits only the lowest radio frequencies and can’t be detected at higher frequencies. The unusual shape and radio spectrum tell a tale of intergalactic gas washing over galaxies and gently revving up electrons spewed out by gargantuan black holes long ago, researchers report in the March 10 Astrophysical Journal.

Spanning 1.2 million light-years, the strange entity lies in Abell 2877, a cluster of galaxies 340 million light-years from Earth. Researchers have dubbed the object the USS Jellyfish, because of its ultra-steep spectrum, or USS, from low to high radio frequencies.

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Astronomers have gotten their first glimpse of the magnetic fields tangled around a black hole.

The Event Horizon Telescope has unveiled the magnetism of the hot, glowing gas around the supermassive black hole at the heart of galaxy M87, researchers report in two studies published online March 24 in the Astrophysical Journal Letters. These magnetic fields are thought to play a crucial role in how the black hole scarfs down matter and launches powerful plasma jets thousands of light-years into space (SN: 3/29/19).

“We’ve known for decades that jets are in some sense powered by accretion onto supermassive black holes, and that the in-spiraling gas and the outflowing plasma are highly magnetized — but there was a lot of uncertainty in the exact details,” says Eileen Meyer, an astrophysicist at the University of Maryland, Baltimore County not involved in the work. “The magnetic field structure of the plasma near the event horizon [of a black hole] is a completely new piece of information.”

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Using the Atacama Large Millimeter/submillimeter Array (ALMA), in which the European Southern Observatory (ESO) is a partner, a team of astronomers has directly measured winds in Jupiter's middle atmosphere for the first time. By analyzing the aftermath of a comet collision from the 1990s, the researchers have revealed incredibly powerful winds, with speeds of up to 1450 kilometers an hour, near Jupiter's poles. They could represent what the team have described as a "unique meteorological beast in our solar system."

Jupiter is famous for its distinctive red and white bands, swirling clouds of moving gas that astronomers traditionally use to track winds in Jupiter's lower atmosphere. Astronomers have also seen, near Jupiter's poles, the vivid glows known as aurorae, which appear to be associated with strong winds in the planet's upper atmosphere. But until now, researchers had never been able to directly measure wind patterns in between these two atmospheric layers, in the stratosphere.

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