Universe Today

October 3, 2020October 3, 2020 by Brian Koberlein

Einstein. Right again

Simulation of M87 black hole showing the motion of plasma as it swirls around the black hole. Credit: L. Medeiros; C. Chan; D. Psaltis; F. Özel; University of Arizona; Institute for Advanced Study

Most of what we know about black holes is based upon indirect evidence. General relativity predicts the structure of a black hole and how matter moves around it, and computer simulations based on relativity are compared with what we observe, from the accretion disks that swirl around a black hole to the immense jets of material they cast off at relativistic speeds. Then in 2019, radio astronomers captured the first direct image of the supermassive black hole in M87. This allows us to test the limits of relativity in a new and exciting way.

October 2, 2020October 2, 2020 by Evan Gough

Did Pioneer See Phosphine in the Clouds of Venus Decades Ago?

Artist’s rendition of a theoretical balloon probe in Venus Clouds c. T.Balint ESA

The discovery of phosphine in Venus’ atmosphere has generated a lot of interest. It has the potential to be a biosignature, though since the discovery, some researchers have thrown cold water on that idea.

But it looks, at least, like the discovery is real, and that one of NASA’s Pioneer spacecraft detected the elusive gas back in 1978. And though it’s not necessarily a biosignature, the authors of a new study think that we need to rethink the chemistry of Venus’ atmosphere.

October 2, 2020October 2, 2020 by Evan Gough

A Supernova Exploded Dangerously Close to Earth 2.5 Million Years Ago

Visible, infrared, and X-ray light image of Kepler's supernova remnant (SN 1604) located about 13,000 light-years away. Credit: NASA, ESA, R. Sankrit and W. Blair (Johns Hopkins University).

In its 4.5 billion year history, Earth has had to run the gauntlet. Numerous catastrophes have imperilled the planet, from massive impacts, to volcanic conflagrations, to frigid episodes of snowball Earth. Yet life persists.

Among all of the hazards that threaten a planet, the most potentially calamitous might be a nearby star exploding as a supernova.

October 2, 2020October 2, 2020 by Paul M. Sutter

What Decides the Shape of Planetary Nebulae? Whatever’s Orbiting a Star When it Dies

This Picture of the Week from the NASA/ESA Hubble Space Telescope shows NGC 5307, a planetary nebula which lies about 10000 light years from Earth. It can be seen in the constellation Centaurus (The Centaur), which can be seen primarily in the southern hemisphere. A planetary nebula is the final stage of a Sun-like star. As such, planetary nebulae allow us a glimpse into the future of our own Solar System. A star like our Sun will, at the end of its life, transform into a red giant. Stars are sustained by the nuclear fusion that occurs in their core, which creates energy. The nuclear fusion processes constantly try to rip the star apart. Only the gravity of the star prevents this from happening. At the end of the red giant phase of a star, these forces become unbalanced. Without enough energy created by fusion, the core of the star collapses in on itself, while the surface layers are ejected outward. After that, all that remains of the star is what we see here: glowing outer layers surrounding a white dwarf star, the remnants of the red giant star’s core. This isn’t the end of this star’s evolution though — those outer layers are still moving and cooling. In just a few thousand years they will have dissipated, and all that will be left to see is the dimly glowing white dwarf.

Planetary nebulae are some of the most beautiful objects in the galaxy, spanning a variety of shapes and sizes. They’re created in the death throes of stars like the sun, and new research sheds light into how they get their distinctive and unique shapes. The answer: anything unlucky enough to orbit that dying star.

October 1, 2020June 12, 2023 by Matt Williams

Beyond “Fermi’s Paradox” XI: What is the Transcension Hypothesis

Welcome back to our Fermi Paradox series, where we take a look at possible resolutions to Enrico Fermi’s famous question, “Where Is Everybody?” Today, we examine the possibility that the reason for the Great Silence is that all the aliens have evolved beyond the need to explore!

In 1950, Italian-American physicist Enrico Fermi sat down to lunch with some of his colleagues at the Los Alamos National Laboratory, where he had worked five years prior as part of the Manhattan Project. According to various accounts, the conversation turned to aliens and the recent spate of UFOs. Into this, Fermi issued a statement that would go down in the annals of history: “Where is everybody?“

This became the basis of the Fermi Paradox, which refers to the disparity between high probability estimates for the existence of extraterrestrial intelligence (ETI) and the apparent lack of evidence. Since Fermi’s time, several possible resolutions have been proposed, including the theory that advanced species eventually “transcend” the physical Universe, also known as the Transcension Hypothesis.

October 1, 2020October 2, 2020 by Matthew Cimone

A Balloon Mission that Could Try to Confirm Life On Venus

Balloon Missions to Venus have been proposed for both exploration as well as colonization c. NASA

So, Venus might have life! But how do we find out for sure?! We need to GO there.

October 1, 2020October 1, 2020 by Matt Williams

Mars Express Finds Even More Ponds of Water Under the Ground on Mars

Radar data collected by ESA’s Mars Express point to a pond of liquid water buried under layers of ice and dust in the south polar region of Mars. Credit: ESA

Evidence of Mars’ watery past is written all over the surface of the planet. Between dried-up river valleys, outflow channels, and sedimentary deposits, it is clear that Mars was once a much different place. But until recently, the mystery of where this water went has remained unsolved. This changed in 2018 when data obtained by the ESA’s Mars Express probe indicated the existence of water beneath the south pole of the planet.

According to the Mars Express probe’s Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS), this body of water is in a 20 km (~12.5 mi) wide area about 1.5 km (~1 mi) beneath the surface. And now, further analysis of the data by a team led by the Roma Tre University has revealed the existence of three new ponds, the largest of which measures about 20 x 30 km (~12.5 x 18.5 mi) and is surrounded by many smaller ponds.

October 1, 2020October 1, 2020 by Evan Gough

A Rogue Earth-Mass Planet Has Been Discovered Freely Floating in the Milky Way Without a Star

An artist's impression of a rogue planet. Image Credit: By Interpott.nrw - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=83123717

If a solar system is a family, then some planets leave home early. Whether they want to or not. Once they’ve left the gravitational embrace of their family, they’re pretty much destined to drift through interstellar space forever, unbound to any star.

Astronomers like to call these drifters “rogue planets,” and they’re getting better at finding them. A team of astronomers have found one of these drifting rogues that’s about the same mass as Mars or Earth.

October 1, 2020October 1, 2020 by Matt Williams

NASA Has a New Challenge to Bring Frozen Samples of the Moon Back to Earth

When astronauts return to the Moon for the first time since the Apollo Era, they will be tasked with conducting some very lucrative science operations. Like their predecessors, this will include a sample-return mission, where they bring back lunar rocks and regolith for study. There have also been proposals that renewed missions to the Moon bring back samples of lunar ice so scientists can determine where the Moon’s water came from.

And it appears NASA was listening and would like some public input on this! To this end, the NASA Tournament Lab and TechConnect Ventures (a n open-innovation platform) have come together to launch the NASA Lunar Deep Freeze Challenge. Basically, NASA is looking for ideas on how cold samples collected in the lunar polar region could be preserved and kept frozen for the return trip to Earth.

October 1, 2020October 1, 2020 by Nancy Graziano

Weekly Space Hangout: September 30, 2020, Dr. John Kiss Discusses the Growth of Plants in Space

This week, we welcome Dr. John Kiss from the University of North Carolina, Greensboro (UNCG). Tonight, Dr. Kiss will be discussing the sensory physiology of plants in space research, including the effect of Mars’ levels of gravity on plant development.