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December 7, 2022December 7, 2022 by Matt Williams

“Early Dark Energy” Could Explain the Crisis in Cosmology

A diagram of the evolution of the observable universe. The Dark Ages are the object of study in this new research, and were preceded by the CMB, or Afterglow Light Pattern. By NASA/WMAP Science Team - Original version: NASA; modified by Cherkash, Public Domain, https://commons.wikimedia.org/w/index.php?curid=11885244 — A diagram of the evolution of the observable universe. Credit: NASA/WMAP/Wikimedia

In 1916, Einstein finished his Theory of General Relativity, which describes how gravitational forces alter the curvature of spacetime. Among other things, this theory predicted that the Universe is expanding, which was confirmed by the observations of Edwin Hubble in 1929. Since then, astronomers have looked farther into space (and hence, back in time) to measure how fast the Universe is expanding – aka. the Hubble Constant. These measurements have become increasingly accurate thanks to the discovery of the Cosmic Microwave Background (CMB) and observatories like the Hubble Space Telescope.

Astronomers have traditionally done this in two ways: directly measuring it locally (using variable stars and supernovae) and indirectly based on redshift measurements of the CMB and cosmological models. Unfortunately, these two methods have produced different values over the past decade. As a result, astronomers have been looking for a possible solution to this problem, known as the “Hubble Tension.” According to a new paper by a team of astrophysicists, the existence of “Early Dark Energy” may be the solution cosmologists have been looking for.

December 6, 2022December 6, 2022 by David Dickinson

Mars at Opposition 2022: The Full Moon Occults Mars Wednesday Night

A rare event transpires Wednesday night, as the Full Moon occults Mars near opposition.

Have you checked out Mars lately? The Red Planet currently rides high to the east at dusk, rising as the Sun sets. We call this opposition season, the biannual span when Mars passes closest to the Earth and offers observers optimal views of the planet. Mars opposition 2022 is special however, as three events converge in one night: Mars at opposition, the Moon reaches Full, and the Moon occults (passes in front of) Mars, all on the evening/morning of Wednesday/Thursday, December 7th/8th.

December 5, 2022December 5, 2022 by Matt Williams

By Looking Back Through Hubble Data, Astronomers Have Identified six Massive Stars Before They Exploded as Core-Collapse Supernovae

The venerable Hubble Space Telescope has given us so much during the history of its service (32 years, 7 months, 6 days, and counting!) Even after all these years, the versatile and sophisticated observatory is still pulling its weight alongside more recent addition, like the James Webb Space Telescope (JWST) and other members of NASA’s Great Observatories family. In addition to how it is still conducting observation campaigns, astronomers and astrophysicists are combing through the volumes of data Hubble accumulated over the years to find even more hidden gems.

A team led by Caltech’s recently made some very interesting finds in the Hubble archives, where they observed the sites of six supernovae to learn more about their progenitor stars. Their observations were part of the Hubble Space Telescope Snapshot program, where astronomers use HST images to chart the life cycle and evolution of stars, galaxies, and other celestial objects. From this, they were able to place constraints on the size, mass, and other key characteristics of the progenitor stars and what they experienced before experiencing core collapse.

December 1, 2022December 1, 2022 by Matt Williams

SpaceX’s Super Heavy Fires 11 of its Engines in a Long-Duration Test

Static engine fire of the BN7 on Nov. 29th, 2022. Credit: SpaceX

SpaceX is at it again! Yesterday (November 29th), the company conducted another static fire test with the Booster 7 (BN7) prototype at its Starbase in Boca Chica, Texas. The test began at 02:42 p.m. EST (11:42 a.m. PST) and saw eleven of the BN7’s thirty-three Raptor 2 engines fire for 13 seconds. While static fire tests have been the norm these past few months, this latest might be the prelude to the orbital test flight Musk has been hinting at for close to a year. News of the successful test was shared via Twitter, while NASA Spaceflight (NSF) shared footage of the test via Youtube.

November 29, 2022December 3, 2022 by Matt Williams

Astronomers Directly Image Debris Disk and find a Jupiter-Sized Planet Orbiting a Sunlike Star

Astronomers with the SHINE collabortion observed a debris disk containing a Super-Jupiter around a young star. Credit: ALMA (ESO/NAOJ/NRAO); M. Weiss (NRAO/AUI/NSF)

According to the most widely-accepted theory, planetary systems form from large clouds of dust and gas that form disks around young stars. Over time, these disks accrete to create planets of varying size, composition, and distance from their parent star. In the past few decades, observations in the mid- and far-infrared wavelengths have led to the discovery of debris disks around young stars (less than 100 million years old). This has allowed astronomers to study planetary systems in their early history, providing new insight into how systems form and evolve.

This includes the SpHere INfrared survey for Exoplanets (SHINE) consortium, an international team of astronomers dedicated to studying star systems in formation. Using the ESO’s Very Large Telescope (VLT), the SHINE collaboration recently directly imaged and characterized the debris disk of a nearby star (HD 114082) in visible and infrared wavelengths. Combined with data from NASA’s Transiting Exoplanet Space Satellite (TESS), they were able to detect a gas giant many times the size of Jupiter (a “Super-Jupiter”) embedded within the disk.

November 25, 2022November 25, 2022 by Matt Williams

Mars Once had Enough Water for a Planet-Wide Ocean 300 Meters Deep

This artist’s impression shows how Mars may have looked about four billion years ago. The young planet Mars would have had enough water to cover its entire surface in a liquid layer about 140 metres deep, but it is more likely that the liquid would have pooled to form an ocean occupying almost half of Mars’s northern hemisphere, and in some regions reaching depths greater than 1.6 kilometres. Credit: ESO/M. Kornmesser

Today, Mars is colloquially known as the “Red Planet” on a count of how its dry, dusty landscape is rich in iron oxide (aka. “rust”). In addition, the atmosphere is extremely thin and cold, and no water can exist on the surface in any form other than ice. But as the Martian landscape and other lines of evidence attest, Mars was once a very different place, with a warmer, denser atmosphere and flowing water on its surface. For years, scientists have attempted to determine how long natural bodies existed on Mars and whether or not they were intermittent or persistent.

Another important question is how much water Mars once had and whether or not this was enough to support life. According to a new study by an international team of planetary scientists, Mars may have had enough water 4.5 billion years ago to cover it in a global ocean up to 300 meters (almost 1,000 feet) deep. Along with organic molecules and other elements distributed throughout the Solar System by asteroids and comets at this time, they argue, these conditions indicate that Mars may have been the first planet in the Solar System to support life.

November 18, 2022November 18, 2022 by David Dickinson

BlueWalker-3 Unfolds, Brightens One-Hundredfold

After months of waiting, we’re getting our first good looks at a fully deployed BlueWalker-3.

A new high-profile satellite may now be visible in a sky over you. We recently wrote about AST Space Mobile’s new BlueWalker-3 satellite, and its potential to be among the brightest objects in the night sky. Launched on September 10^th, 2022 an a SpaceX Falcon-9 rocket along with the Starlink Group 4-2 batch, BlueWalker-3 is the first of the company’s planned mega-constellation of 110 BlueBird satellites set to be deployed by the end of 2024 for worldwide communication.

November 17, 2022November 17, 2022 by David Dickinson

Are We in for a Leonid Outburst Friday Night?

Leonid from 2001 — A lone Leonid meteor from 2001. Image credit and copyright: Frankie Lucena.

The November Leonid meteors may produce a surprise outburst this weekend.

If forecasters are right, a notorious meteor shower may put on a surprise showing soon, right after its expected peak. The meteor shower in question is the November Leonids. Most years, the Leonids are really nothing to wake up early for, producing an average hourly rate of 10 meteors an hour, barely double the background sporadic rate. But every 33 years or so, the Leonids are the source of great storms of meteors, as the Earth plows headlong into the stream of debris laid down by comet 55P/Tempel-Tuttle on its 33-year orbit around the Sun.

November 16, 2022November 16, 2022 by Matt Williams

Greenland’s ice Loss is Worse Than We Thought

Cumulative melt days on the Greenland Ice Sheet for the 2022 melt season (left) and difference from the 1981 to 2010 average melt days for the same period (right). Credit: NSIDC/T. Mote, University of Georgia

Climate change is the single greatest threat facing our planet today. Thanks to excess carbon emissions that have been growing steadily since the mid-20th century, average temperatures continue to rise worldwide. This leads to feedback mechanisms, such as rising sea levels, extreme weather, drought, wildfires, and glacial melting. This includes the Arctic Ice Pack, the East Antarctic glacier, and the Greenland Ice Sheet (GrIS), which are rapidly melting and increasing global sea levels.

Worse than that, the disappearance of the world’s ice sheets means that Earth’s surface and oceans absorb more heat, driving global temperatures even further. According to a new NASA-supported study by an international team of Earth scientists and glaciologists, the Greenland Ice Sheet is melting at an accelerating rate, much faster than existing models predict. According to these findings, far more ice will be lost from Greenland during the 21st century, which means its contribution to sea-level rise will be significantly higher.

November 16, 2022November 16, 2022 by Matt Williams

What Would Asteroid Mining do to the World's Economy?

Artist's impression of an astronaut conducting an EVA with an asteroid. Credit: NASA

About a decade ago, the prospect of “asteroid mining” saw a massive surge in interest. This was due largely to the rise of the commercial space sector and the belief that harvesting resources from space would soon become a reality. What had been the stuff of science fiction and futurist predictions was now being talked about seriously in the business sector, with many claiming that the future of resource exploitation and manufacturing lay in space. Since then, there’s been a bit of a cooling off as these hopes failed to materialize in the expected timeframe.

Nevertheless, there is little doubt that a human presence in space will entail harvesting resources from Near Earth Asteroids (NEAs) and beyond. In a recent paper, a team of researchers from the University of Nottingham in Ningbo, China, examined the potential impact of asteroid mining on the global economy. Based on their detailed assessment that includes market forces, environmental impact, asteroid and mineral type, and the scale of mining, they show how asteroid mining can be done in a way that is consistent with the Outer Space Treaty (i.e., for the benefit of all humanity).