Astronomy Archives

September 17, 2020September 17, 2020 by Brian Koberlein

Colliding Neutron Stars Don’t Make Enough Gold to Explain What We See in the Universe

gamma-ray burst from neutron star merger — Artist rendering of colliding neutron stars. Credit: Robin Dienel/Carnegie Institution for Science

In the beginning, the universe created three elements: hydrogen, helium, and lithium. There isn’t much you can do with these simple elements, other than to let gravity collapse them into stars, galaxies, and black holes. But stars have the power of alchemy. Within their hearts, they can fuse these elements into new ones. Carbon, nitrogen, oxygen, and others, all up to the heavy element of iron. When these first stars exploded, they scattered the new elements across the cosmos, creating planets, new stars, and even us.

September 17, 2020September 17, 2020 by Evan Gough

Check Out How Big the Planets and the Moon Will be in Our Sky Over the Next Two Years

This is a screenshot of a data visualization video. It shows the apparent sizes of Solar System objects from our Earthly vantage point. Image Credit: James O'Donoghue

Everything in space is moving. Galaxies collide and merge, massive clouds of gas migrate, and asteroids, comets, and rogue planets zip around and between it all. And in our own Solar System, the planets follow their ancient orbits.

Now a new data visualization shows us just how much our view from Earth changes in two years, as the orbits of the planets change the distance between us and our neighbours.

September 16, 2020September 21, 2020 by Evan Gough

Missions Are Already Being Planned to Figure Out What’s Creating the Biosignature on Venus

The planet Venus, as imaged by the Magellan mission. Credit: NASA/JPL

The discovery of phosphine in the upper clouds in Venus’ atmosphere has generated a lot of excitement. On Earth, phosphine is produced biologically, so it’s a sign of life. If it’s not produced by life, it takes an enormous amount of energy to be created abiologically.

On other planets like Jupiter, there’s enough energy to produce phosphine, so finding it there isn’t surprising. But on a small rocky world like Venus, where there’s no powerful source of energy, its existence is surprising.

This discovery clearly needs some more investigating.

September 16, 2020September 16, 2020 by Evan Gough

Uranus’ Moons are Surprisingly Similar to Dwarf Planets in the Kuiper Belt

Astronomer William Herschel discovered Uranus—and two of its moons—230 years ago. Now a group of astronomers working with data from the telescope that bears his name, the Herschel Space Observatory, have made an unexpected discovery. It looks like Uranus’ moons bear a striking similarity to icy dwarf planets.

The Herschel Space Observatory has been retired since 2013. But all of its data is still of interest to researchers. This discovery was a happy accident, resulting from tests on data from the observatory’s camera detector. Uranus is a very bright infrared energy source, and the team was measuring the influence of very bright infrared objects on the camera.

The images of the moons were discovered by accident.

September 15, 2020September 15, 2020 by Evan Gough

Astronomers Have Discovered a 2-km Asteroid Orbiting Closer to the Sun than Venus

An artist's conception of an NEO asteroid orbiting the Sun. Credit: NASA/JPL.

Astronomers have painstakingly built models of the asteroid population, and those models predict that there will be ~1 km sized asteroids that orbit closer to the Sun than Venus does. The problem is, nobody’s been able to find one. Until now.

Astronomers working with the Zwicky Transient Facility say they’ve finally found one. But this one’s bigger, at about 2 km. If its existence can be confirmed, then asteroid population models may have to be updated.

September 15, 2020September 15, 2020 by Evan Gough

The Milky Way is Already Starting to Digest the Magellanic Clouds, Starting With Their Protective Halos of Hot Gas

A view of the gas in the Magellanic System as it would appear in the night sky. The Magellanic Corona covers the entire sky while the Magellanic Stream is seen as gas flowing away from the two dwarf galaxies, the Large and the Small Magellanic Clouds. This image, taken directly from the numerical simulations, has been modified slightly for aesthetics. Image Credit: COLIN LEGG / SCOTT LUCCHINI

Massive galaxies like our Milky Way gain mass by absorbing smaller galaxies. The Large Magellanic Cloud and the Small Magellanic Cloud are irregular dwarf galaxies that are gravitationally bound to the Milky Way. Both the clouds are distorted by the Milky Way’s gravity, and astronomers think that the Milky Way is in the process of digesting both galaxies.

A new study says that process is already happening, and that the Milky Way is enjoying the Magellanic Clouds’ halos of gas as an appetizer, creating a feature called the Magellanic Stream as it eats. It also explains a 50 year old mystery: Why is the Magellanic Stream so massive?

September 15, 2020September 15, 2020 by Paul M. Sutter

Extreme galaxies depend on extreme conditions for their formation

The spiral pattern shown by the galaxy NGC 2275 in this image from the NASA/ESA Hubble Space Telescope is striking because of its delicate, feathery nature. Credit: ESA/Hubble & NASA, J. Lee and the PHANGS-HST Team; Acknowledgment: Judy Schmidt (Geckzilla)

Some galaxies are too small, and some galaxies are too big, while others are just right. A new survey of the nearby Virgo cluster has potentially revealed why extreme galaxies are the wrong size, and how they might be connected.

September 14, 2020September 14, 2020 by Paul M. Sutter

A beautiful picture of Saturn’s heavily-cratered moon Mimas, processed by @kevinmgill

Mimas, as imaged by NASA's Cassini spacecraft and processed by @kevinmgill

The Cassini mission to Saturn took many images of Mimas, one of the smallest moons in the solar system. And now you can view it in all its icy, cratered glory, thanks to the work of Kevin Gill.

September 14, 2020September 14, 2020 by Evan Gough

Did Scientists Just Find Signs of Life on Venus?

This artistic impression depicts Venus. Astronomers at MIT, Cardiff University, and elsewhere may have observed signs of life in the atmosphere of Venus. Credits:Image: ESO (European Space Organization)/M. Kornmesser & NASA/JPL/Caltech

A team of scientists has just published a paper announcing their discovery of a peculiar chemical in the cloudtops of Venus. As far as scientists can tell, this chemical, called phosphine, could only be produced by living processes on a planet like Venus. So the whole internet is jumping on this story.

But did they find signs of life? Or is there another explanation?

September 14, 2020September 14, 2020 by Andy Tomaswick

Australian Telescope Just Scanned 10 million Stars For Any Sign of Extraterrestrial Signals. No sign.

One of the most important results of science is the negative result. If something doesn’t work or a hypothesis is disproven, often it’s not widely reported or disseminated. That is a shame. However, science is getting better at incorporating negative results into its reporting system, which has resulted in publications like the Journal of Negative Results, which covers biomedicine.

Unfortunately there isn’t a similar journal for Astronomy. At least not yet. But the field could really use one. There are plenty of disproven hypotheses that don’t see the light of day in academically peer reviewed publications. When it comes to topics like SETI, sometimes those negative results are extremely important, as it lends credence to one of the most important hypotheses out there – that we are alone in the universe. Papers that cover negative SETI results can be accepted into journals that otherwise might not accept a paper centered around not finding anything. That’s what happened recently when a team of astronomers from Australia and elsewhere used the Murchison Widefield Array (MWA) to search a patch of sky that included 10 million stars. The negative results was that they did not see a single sign of intelligent life anywhere in those 10 million stars.