Universe Today

October 3, 2021October 3, 2021 by Scott Alan Johnston

When Did Photosynthesis Begin?

Sometime around 2.4 billion years ago, a nascent planet Earth underwent one of the most dramatic changes in its history. Known as the Great Oxidation Event, this period saw Earth’s atmosphere suddenly bloom with (previously scarce) molecular oxygen. The rapid alteration of the atmosphere’s composition was nothing short of a cataclysm for some early lifeforms (at the time, mostly simple celled prokaryotes). Anaerobic species – those that dwell in oxygen-free environments – experienced a near extinction-level event. But the Great Oxidation was also an opportunity for other forms of life to thrive. Oxygen in the atmosphere tempered the planetary greenhouse effect, turning methane into the less potent carbon dioxide, and ushering in a series of ice ages known as the Huronian Glaciation. But oxygen is an energy-rich molecule, and it also bolstered diversity and activity on the planet, as a powerful new source of fuel for living organisms.

The cause of this dramatic event? The tiniest of creatures: little ocean-dwelling cyanobacteria (sometimes known as blue-green algae) that had developed a new super-power never before seen on planet Earth: photosynthesis. This unique ability – to gain energy from sunlight and release oxygen as a waste product – was a revolutionary step for so small a critter. It quite literally changed the world.

October 3, 2021October 3, 2021 by Matt Williams

Communication With Mars is About to Become Impossible (for two Weeks)

Every two years, Mars enters what is known as a “Solar Conjunction,” where its orbit takes it behind the Sun relative to Earth. During these periods, the hot plasma regularly expelled by the Sun’s corona can cause interference with radio signals transmitted between Earth and Mars. To avoid signal corruption and the unexpected behaviors that could result, NASA and other space agencies declare a moratorium on communications for two weeks.

What this means is that between Oct. 2nd and Oct. 16th, all of NASA’s Mars missions will experiencing what is known as a “commanding moratorium.” This will consist of NASA sending a series of simple commands to its missions in orbit, which will then be dispatched to landers and rovers on the surface. These simple tasks will keep all of the robotic Martian explorers busy until regular communications can be established.

October 3, 2021October 4, 2021 by Brian Koberlein

Future Telescopes Could be Seeing the Wrong Planets

NASA’s Wide Field Infrared Survey Telescope (WFIRST) is now named the Nancy Grace Roman Space Telescope, after NASA’s first Chief of Astronomy. Credits: NASA

We have discovered thousands of exoplanets in recent years, including some that are Earth-sized and potentially habitable. But we haven’t seen many of those worlds. Most of the exoplanets we’ve found have been discovered using the transit method, which involves watching the brightness of a star dip as a planet passes in front of it. We can learn the size and sometimes the mass from these dips, but we have no idea what the world looks like, or whether it has a breathable atmosphere.

October 1, 2021October 1, 2021 by Evan Gough

Rogue Planets Could be Habitable

An artist's illustration of a rogue planet, dark and mysterious. Image Credit: NASA

The search for potentially habitable planets is focused on exoplanets—planets orbiting other stars—for good reason. The only planet we know of with life is Earth and sunlight fuels life here. But some estimates say there are many more rogue planets roaming through space, not bound to or warmed by any star.

Could some of them support life?

September 30, 2021September 30, 2021 by Andy Tomaswick

Some of the Moon’s Craters are so Dark, it Takes AI to see What’s Inside Them

There is no dark side of the Moon. But there are dark spots on it – specifically at the bottom of craters that are never reached by any sunlight no matter where the Moon is facing. These areas have intrigued scientists for decades, in no small part because lack of sunlight means a lower temperature, allowing frozen materials to stay frozen. In other words, there may be water in them thar craters. And water will be the lifeblood of any future permanent crewed lunar mission.

Unfortunately, lack of sunlight also means it’s challenging to see what’s at the bottom of those craters. The closest scientists have come was when LCROSS, a NASA moon mission, fired a projectile into the crater Cabeus and analyzed the resultant dust cloud, which contained a relatively high amount of water. But so far, no one has been able to image what water is in those craters directly.

September 30, 2021September 30, 2021 by Evan Gough

BepiColombo Meets Mercury for the First Time on October 1

New research suggests that Mercury is still contracting and shrinking. Credits: NASA/JHUAPL/Carnegie Institution of Washington/USGS/Arizona State University

BepiColombo made a quick visit to Venus in August and is on to its next rendezvous. On October 1st it’ll perform a flyby of Mercury, the spacecraft’s eventual destination. This visit is just a little flirtation—one of six—ahead of its eventual orbital link-up with Mercury in late 2025.

The quick visit will yield some scientific results, though, and they’ll be just a taste of what’s ahead in BepiColumbo’s one-year mission to Mercury.

September 30, 2021September 30, 2021 by Andy Tomaswick

Starlink can be Used as a Navigation System too

Starlink keeps growing, and so do its capabilities. Lately, even people outside of SpaceX have even been developing capabilities for it. A team of researchers from the Ohio State University (OSU) and the University of California Irvine (UCI) has developed a way to use Starlinks networked satellites as a basic navigation tool.

September 30, 2021September 30, 2021 by Andy Tomaswick

Giant Balls of Mush Made From Ammonia and Water Form in the Atmospheres of Uranus and Neptune

One advantage to planetary science is that insights from one planet could explain phenomena on another. We understand Venus’ greenhouse gas effect from our own experience on the Earth, and Jupiter and Saturn share some characteristics. But Jupiter also provides insight into other, farther out systems, such as Uranus and Neptune. Now, a discovery from a spacecraft orbiting Jupiter might have solved a long-standing mystery about Uranus and Neptune – where has all the ammonia gone?

September 29, 2021September 29, 2021 by Evan Gough

Even the Quiet Supermassive Black Holes are Blasting out Neutrinos and Gamma Rays

Is there anywhere in the Universe where we can escape from radiation? Certainly not here on Earth. And not in space itself, which is filled with diffuse radiation in the form of gamma rays and neutrinos. Scientists have struggled to explain where all those gamma rays and neutrinos come from. A trio of researchers is proposing a source for all that radiation in a new paper: resting black holes.

September 29, 2021September 29, 2021 by Nancy Atkinson

Landsat 9 Joins a Fleet of Earth Observation Satellites

Landsat 9 lifted off from Vandenberg Space Force Base on September 27, 2021 on an an Atlas V 401 rocket. Credit: NASA

Earth has a new eye in orbit to monitor our changing planet.

Landsat 9 launched on September 27, 2021 continuing the Landsat family of satellite’s nearly 50-year tradition of making critical observations to help with energy and water management, forest monitoring, human and environmental health, urban planning, disaster recovery and agriculture.