Posted on by Matt Williams

Microbes Found That Survive on the by-Products of Radioactive Decay

The rocks seen here along the shoreline of Lake Salda in Turkey were formed over time by microbes that trap minerals and sediments in the water. These so-called microbialites were once a major form of life on Earth and provide some of the oldest known fossilized records of life on our planet. NASA's Mars 2020 Perseverance mission will search for signs of ancient life on the Martian surface. Studying these microbial fossils on Earth has helped scientists prepare for the mission. Image Credit: NASA/JPL-Caltech

In addition to investigating the big questions about life in our Universe (origins, evolution, distribution, etc.), one of the chief aims of astrobiologists is to characterize extraterrestrial environments to determine if life could exist there. However, there are still unresolved questions about the range of conditions under which life can survive and thrive. Placing better constraints on this will help astrobiologists search for life beyond Earth.

To get a better understanding of how ecosystems can exist beneath the ocean floor (so far from the Sun) a team of researchers led by the University of Rhode Island’s Graduate School of Oceanography (GSO) conducted a study on microbes in ancient seafloor sediment. What they found, to their surprise, was that these lifeforms are sustained primarily by chemicals created by the natural irradiation of water molecules.

Continue reading “Microbes Found That Survive on the by-Products of Radioactive Decay”
Posted on by Andy Tomaswick

Organic Material Found on an Asteroid Sample Returned by Hayabusa 1

Panspermia is an idea that has been around for a long time.  It was first mentioned in the 5th century BC by Anaxagoras, one of the most prominent pre-Socratic philosophers.  The problem with the theory is that there’s never really been any evidence to back it up.  That lack of evidence has changed dramatically in the last 20 or so years, and recently more data has been added to that dataset.  A team from Royal Holloway, part of the University of London, found organic material and water in a sample of Itokawa, the asteroid the first Hayabusa mission visited over 10 years ago.

Continue reading “Organic Material Found on an Asteroid Sample Returned by Hayabusa 1”
Posted on by Nancy Atkinson

The Galápagos Islands From Space

A satellite image from the Copernicus Sentinel-2 mission showing the Galápagos Islands – a volcanic archipelago situated some 1000 km west of Ecuador in the Pacific Ocean. Credit: Modified Copernicus Sentinel data (2020), processed by ESA.

The Galápagos Islands hold an honored place in science history. I often wonder, if Charles Darwin could have seen this volcanic archipelago from this vantage point – a satellite view – how might have that aided or changed his research on evolution?

Continue reading “The Galápagos Islands From Space”
Posted on by Brian Koberlein

What's the Connection Between Stellar-Mass Black Holes and Dark Matter?

Artist view of a black hole in the middle of solar system. Credit: Petr Kratochvil/PublicDomainPictures CC0

Imagine you are a neutron star. You’re happily floating in space, too old to fuse nuclei in your core anymore, but the quantum pressure of your neutrons and quarks easily keeps you from collapsing under your own weight. You look forward to a long stellar retirement of gradually cooling down. Then one day you are struck by a tiny black hole. This black hole only has the mass of an asteroid, but it causes you to become unstable. Gravity crushes you as the black hole consumes you from the inside out. Before you know it, you’ve become a black hole.

Continue reading “What's the Connection Between Stellar-Mass Black Holes and Dark Matter?”
Posted on by Paul M. Sutter

Researchers Discover the Source of the Sun’s Most Dangerous High-Energy Particles

Sometimes the sun spits out high-energy particles which slam into the Earth, potentially disrupting our sensitive electronics. New research has found that these particles originate in the plasma of the sun itself, and are trapped there by strong magnetic fields. When those fields weaken, the particles blast out.

Continue reading “Researchers Discover the Source of the Sun’s Most Dangerous High-Energy Particles”
Posted on by Matt Williams

Fantastic Analysis of SN-10 Landing and Explosion by Scott Manley

Credit: SpaceX

Update: Yesterday (March 9th), Elon Musk shared the reason for the explosion via Twitter. According to Musk, the problem originated with the one Raptor engine used to slow the SN10 down before landing.

“SN10 engine was low on thrust due (probably) to partial helium ingestion from fuel header tank,” he tweeted. “Impact of 10m/s crushed legs & part of skirt. Multiple fixes in work for SN11.“

On March 3rd, 2021, SpaceX conducted a third high-altitude flight test with one of their Starship prototypes (SN10). This time around, the prototype managed to achieve an apogee of 10 km (6.2 mi), a controlled descent relying on nothing but its aerodynamic surfaces (the “belly-flop”), and even managed to land successfully. However, a few minutes after it stuck the landing, the SN10 exploded on the landing pad.

Whereas the SN8 and SN9 explosions were attributed to problems that took place during engine reignition, the cause of the SN10 explosion was not as clear. Thankfully, astrophysicist and Youtube personality Scott Manley (Twitter handle @DJSnM) has offered his take on what might have caused it. Using SpaceX’s footage of the SN10 flight test, he suggests that a slightly-harder-than-intended landing and a fuel tank rupture were responsible.

Continue reading “Fantastic Analysis of SN-10 Landing and Explosion by Scott Manley”
Posted on by Paul M. Sutter

Did Supermassive Black Holes Form Directly From Dark Matter?

This illustration depicts a gas halo surrounding a quasar in the early Universe. The quasar, in orange, has two powerful jets and a supermassive black hole at its centre, which is surrounded by a dusty disc. The gas halo of glowing hydrogen gas is represented in blue. A team of astronomers surveyed 31 distant quasars, seeing them as they were more than 12.5 billion years ago, at a time when the Universe was still an infant, only about 870 million years old. They found that 12 quasars were surrounded by enormous gas reservoirs: halos of cool, dense hydrogen gas extending 100 000 light years from the central black holes and with billions of times the mass of the Sun. These gas stashes provide the perfect food source to sustain the growth of supermassive black holes in the early Universe.

Supermassive black holes are just a little bit too supermassive – astronomers have difficulty explaining how they got so big so quickly in the early universe. So maybe it’s time for a new idea: perhaps giant black holes formed directly from dark matter.

Continue reading “Did Supermassive Black Holes Form Directly From Dark Matter?”