Evan Gough, Author at Universe Today

February 14, 2022February 14, 2022 by Evan Gough

Astronomers Scan the Center of the Milky Way for Any Sign of Intelligent Civilizations. Nothing but Silence.

This is an image of the center of the Milky Way. The bright white area right of center is home of the supermassive black hole Sagittarius A star. Image Credit: By NASA/JPL-Caltech/ESA/CXC/STScI - http://photojournal.jpl.nasa.gov/catalog/PIA12348See also http://www.spacetelescope.org/images/opo0928a/ and http://hubblesite.org/newscenter/archive/releases/2009/28/image/a/, Public Domain, https://commons.wikimedia.org/w/index.php?curid=24958921

Are there civilizations somewhere else in the Universe? Somewhere else in the Milky Way? That’s one of our overarching questions, and an answer in the affirmative would be profound.

Humanity’s pursued the Search for Extraterrestrial Intelligence (SETI) in one form or another since shortly after the advent of radio waves in the early 20th century. Efforts have waxed and waned over the decades, but the search has never been completely abandoned.

The search detected transient hints in the form of unexplained radio waves in the past, but nothing that comprises reliable evidence. Now a new search for technosignatures in the Milky Way’s center has turned up nothing.

February 14, 2022February 14, 2022 by Evan Gough

Water was Already Here Before the Earth Formed

Earth as seen by the JUNO spacecraft in 2013. Credit: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill.

Where did Earth’s water come from? That’s one of the most compelling questions in the ongoing effort to understand life’s emergence. Earth’s inner solar system location was too hot for water to condense onto the primordial Earth. The prevailing view is that asteroids and comets brought water to Earth from regions of the Solar System beyond the frost line.

But a new study published in the journal Nature Astronomy proposes a further explanation for Earth’s water. As the prevailing view says, some of it could’ve come from asteroids and comets.

But most of the hydrogen was already here, waiting for Earth to form.

February 11, 2022February 11, 2022 by Evan Gough

We Might Know Why Mars Lost its Magnetic Field

This figure shows a cross-section of the planet Mars revealing an inner, high density core buried deep within the interior. Dipole magnetic field lines are drawn in blue, showing the global scale magnetic field that one associates with dynamo generation in the core. Mars must have one day had such a field, but today it is not evident. Perhaps the energy source that powered the early dynamo has shut down. The differentiation of the planet interior - heavy elements like iron sinking towards the center of the planet - can provide energy as can the formation of a solid core from the liquid. Credit: NASA/JPL/GSFC

Mars is a parched planet ruled by global dust storms. It’s also a frigid world, where night-time winter temperatures fall to -140 C (-220 F) at the poles. But it wasn’t always a dry, barren, freezing, inhospitable wasteland. It used to be a warm, wet, almost inviting place, where liquid water flowed across the surface, filling up lakes, carving channels, and leaving sediment deltas.

But then it lost its magnetic field, and without the protection it provided, the Sun stripped away the planet’s atmosphere. Without its atmosphere, the water went next. Now Mars is the Mars we’ve always known: A place that only robotic rovers find hospitable.

How exactly did it lose its magnetic shield? Scientists have puzzled over that for a long time.

February 9, 2022February 9, 2022 by Evan Gough

Asteroids are Dangerous, but They Might Also be the Key to Life on Earth

This artist's conception shows how families of asteroids are created. Credit: NASA/JPL-Caltech

Trying to piece together the appearance of life on Earth is a little like looking through a kaleidoscope. There are competing theories for where Earth’s water came from, and there’s incomplete evidence for how the Moon formed and what role it played in life’s emergence. There are a thousand other questions, each with competing answers. Sometimes, contradictory research is published within days of each other.

But that’s nature, and that’s part of the thrill of science. There’s rigorous determination behind all the evidence and inquiry, and the kaleidoscope calms down over time. Order emerges, and the picture becomes clearer.

February 8, 2022February 8, 2022 by Evan Gough

Massive Rocky Planets Probably Don’t Have big Moons

The Earth straddling the limb of the Moon, as seen from above Compton crater on the lunar farside, taken by the Lunar Reconnaissance Orbiter spacecraft. Credit: NASA/GSFC/Arizona State University.

The Moon has orbited Earth since the Solar System’s early days. Anyone who’s ever spent time at the ocean can’t fail to notice the Moon’s effect. The Moon drives the tides even in the world’s most remote inlets and bays. And tides may be vital to life’s emergence.

But if Earth were more massive, the Moon may never have become what it is now. Instead, it would be much smaller. Tides would be much weaker, and life may not have emerged the way it did.

February 4, 2022February 4, 2022 by Evan Gough

A Second Generation of Planets can Form Around a Dying Star

An illustration of a protoplanetary disk. The solar system formed from such a disk. Astronomers suggest this birthplace was protected by a larger filament of molecular gas and dust early in history. Credit: NASA/JPL-Caltech/T. Pyle (SSC)

When young stars coalesce out of a cloud of molecular hydrogen, a disk of leftover material called a protoplanetary disk surrounds them. This disk is where planets form, and astronomers are getting better at peering into those veiled environments and watching embryonic worlds take shape. But young stars aren’t the only stars with disks of raw material rotating around them.

Some old, dying stars also have disks. Can a second generation of planets form under those conditions?

February 3, 2022February 3, 2022 by Evan Gough

There are Places Where Salty Water Could Emerge Onto the Surface of Mars

A computer generated view of Mars, with an area including Gale Crater beginning to catch morning light. Image Credit: NASA/JPL-Caltech

The existence of water on Mars is a contentious subject. We know there used to be water on the surface of the planet, though it’s long gone now. We know there’s frozen water underground in the world, and we know there’s water vapour in the air. But life needs liquid water.

Could there be liquid water on Mars?

A new study shows how salty water could emerge from the atmosphere onto Mars’ surface under the right conditions.

February 2, 2022February 2, 2022 by Evan Gough

North Korea Releases Pictures of Earth They Say Were Taken From Space

This is an image taken with a camera onboard North Korea's Hwasong-12 missile during a test launch in January 2022. Image Credit: NKNews.org

North Korea released some pictures they say come from their recent missile test. The missile they tested—the intermediate-range Hwasong-12—can reach the U.S. territory of Guam. According to most North Korea observers, the country hopes the tests will bring the U.S. back to the negotiating table.

February 2, 2022February 2, 2022 by Evan Gough

Latest Hubble Image Shows the Star-Forming Chamaeleon Cloud

This is a Hubble composite image of the Chamaeleon I cloud complex. Image Credit: NASA, ESA, K. Luhman and T. Esplin (Pennsylvania State University), et al., and ESO; Processing: Gladys Kober (NASA/Catholic University of America)

Stars form inside vast collections of molecular hydrogen called molecular clouds, sometimes called stellar nurseries or star forming regions. Instabilities in the clouds cause gas to collapse in on itself, and when enough material gathers and the density reaches a critical stage, a star begins its life of fusion.

But molecular clouds aren’t always alone. They often exist in association with other clouds, and astronomers call these formations Cloud Complexes. The Chamaeleon Cloud Complex (CCC) is one of the closest active star forming regions to Earth. It’s further divided into three substructures called dark clouds, or dark nebula. They are Chamaeleon 1 (Cha1), Chamaeleon 2, and Chamaeleon 3.

NASA created a new composite image of Chamaeleon 1 based on Hubble images, and the vivid panorama brings Chamaeleon I to life.

February 1, 2022February 1, 2022 by Evan Gough

A Chinese Space Tug Just Grappled a Dead Satellite

This graphic shows a satellite in geostationary orbit. Image Credit: NASA

A Chinese satellite pulled a defunct navigation satellite out of the way of other satellites on January 22nd. The satellite, called SJ-21, appeared to operate as a space tug when it grappled onto the navigation satellite from the Chinese CompassG2 network. The operation details didn’t come from Chinese authorities but a report by ExoAnalytic Solutions, a commercial space monitoring company.

Chinese authorities are tight-lipped about the operation, but what can observations tell us about Chinese capabilities?