Universe Today

August 14, 2022August 14, 2022 by Brian Koberlein

Hot Stars Blast Away at gas Giants Until Only Their Rocky Cores Remain

Artist view of a Neptune-sized planet orbiting a blue A-type star. Credit: Steven Giacalone, UC Berkeley

In our solar system, we have two types of planets. Small, warm, rocky worlds populate the inner region, while the outer region has cold gas giants. Intuitively this makes a lot of sense. When the solar system was forming, the Sun’s light and heat must have pushed much of the gas toward the outer system, leaving heavier dust and rock to form the inner worlds. Giants could only grow in the cold, dark outer solar system. But we now know our solar system is more the exception than the rule. Many star systems have large gas planets that orbit close to their stars. These hot Jupiters and hot Neptunes are unlike anything in our solar system, and astronomers are keen to understand what they may be like.

August 14, 2022August 14, 2022 by Anton Pozdnyakov

JWST’s Science, Surgeon Robot for ISS, Booster 7 Test Fire

James Webb delivers scientific results, SLS and Starship go closer to their maiden flights, remote surgery robot is going to the ISS, Perseverance continues to find weird stuff on Mars, and Hubble is still going strong. All this and more in this week’s episode of Space Bites. All this and more in this week’s episode of Space Bites.

August 13, 2022August 13, 2022 by Paul M. Sutter

MIT Researchers Propose Space Bubbles to Stop Climate Change

Artist's conception of bubbles used to reduce sunlight to combat climate change (Image credit: MIT)

Climate change is a real problem. Human caused outputs of greenhouse gases like carbon dioxide and methane are the main driver of an unprecedented rise in global average temperatures at a speed never before seen in the Earth’s geologic record. The problem is so bad that any attempts to mitigate greenhouse gas emissions may be too little and too late. And so a team based at the Massachusetts Institute of Technology have proposed a radical new solution: bubbles…in space.

August 13, 2022August 13, 2022 by Carolyn Collins Petersen

In Wildly Different Environments, Stars End Up Roughly the Same

When you look at a region of the sky where stars are born, you see a cloud of gas and dust and a bunch of stars. It’s really a beautiful sight. In most places, the stars all end up being about the same mass. That mass is probably the most important factor you want to know about it. It directs how long the star will live and what its future will be like. But, what determines its mass and the mass of its siblings in a stellar nursery? Is there some governing force that tells them how massive they’ll be? It turns out that the stars do it for themselves.

August 13, 2022August 13, 2022 by Brian Koberlein

Primordial Black Holes Could Have Triggered the Formation of Supermassive Black Holes

Artist view of merging black holes in the early universe. Credit: LIGO/Caltech/MIT/R. Hurt (IPAC)

The early moments of the universe were turbulent and filled with hot and dense matter. Fluctuations in the early universe could have been great enough that stellar-mass pockets of matter collapsed under their own weight to create primordial black holes. Although we’ve never detected these small black holes, they could have played a vital role in cosmic evolution, perhaps growing into the supermassive black holes we see today. A new study shows how this could work, but also finds the process is complicated.

August 12, 2022August 12, 2022 by Matt Williams

Why Betelgeuse Dimmed

Credit: NASA, ESA, and E. Wheatley (STScI)

Betelgeuse, the big reddish star that is the second brightest point in the constellation Orion (after Rigel), has been puzzling astronomers for years. Starting in October 2019, Belegeuse began to dim considerably, eventually reaching 1/3rd of its normal brightness a few months later. And then, just as mysteriously, it began to brighten again and (as of February 2022) has remained in a normal brightness range. The most likely reason appeared to be a circumstellar dust cloud rather than any changes in the star’s intrinsic brightness.

Using data from NASA’s Hubble Space Telescope (HST) and several other observatories, astronomers have concluded that a Surface Mass Ejection (SME) was the culprit. This event occurred in 2019 when Betelgeuse released a substantial mass of material that cooled to form a circumsolar dust ring, obscuring the star. In contrast to what regularly happens with our Sun during a Coronal Mass Ejections (CME), Betelgeuse ejected roughly 400 billion times as much mass as a typical CME. This is the first time something of this nature has been seen in a normal star’s behavior.

August 12, 2022August 12, 2022 by Brian Koberlein

Thanks to Gaia we Know Exactly how and When the Sun Will die

How different types of stars live and die. Credit: ESA

Our Sun is doomed. Billions of years from now, the Sun will deplete its hydrogen fuel and swell to a red giant before becoming a white dwarf. It’s a well-known story, and one astronomers have understood for decades. Now, thanks to the latest data from Gaia, we know the Sun’s future in much greater detail.

August 12, 2022August 12, 2022 by David Dickinson

Starlink Satellites Are Still Bright

The new generation of Starlink satellites remain above the accepted brightness threshold.

It’s one of the stranger sights of the modern Space Age. Recently, we found ourselves under the relatively dark skies of southern Spain. Sure enough, within a few minutes, we caught sight of a chain of flashing ‘stars’ winking in and out of view in quick succession.

August 11, 2022August 12, 2022 by Laurence Tognetti

Impacts From Interstellar Objects Should Leave Very Distinct Craters

In a recent study submitted to Earth and Planetary Astrophysics, a team of researchers from Yale University investigated how to identify impact craters that may have been created by Interstellar Objects (ISOs). This study is intriguing as the examination of ISOs has gained notable interest throughout the scientific community since the discoveries and subsequent research of ‘Oumuamua and Comet 2I/Borisov in 2017 and 2019, respectively. In their paper, the Yale researchers discussed how the volume of impact melt within fixed-diameter craters could be a possible pathway for recognizing ISO craters, as higher velocity impacts produce greater volumes of impact melt.

August 11, 2022August 12, 2022 by Carolyn Collins Petersen

Here’s a Sneak Preview of What It’ll Look Like When the Milky Way and Andromeda Galaxies Collide

When big spiral galaxies collide, they don’t end up as one really big spiral. Instead, they create a humongous elliptical galaxy. That’s the fate awaiting the Andromeda Galaxy and our Milky Way. They’ll tangle in a galactic dance starting in a few billion years. Want to know what it’s going to look like when the action starts? The Gemini North telescope in Hawai’i just released a stunning image of two galaxies like ours tangling it up. These are NGC 4568 and NGC 4567 and their interaction provides a sneak peek at our galactic neighborhood in the distant future.