Philip Plait's Blog, page 3

JWST sees carbon dioxide in the atmosphere of an exoplanet for the first time

Chalk up another first for JWST: Observations of an exoplanet have unambiguously detected the presence of carbon dioxide in its atmosphere, something that has never been done before.

Small black holes near big black holes may tear apart and eat stars

You’d think black holes would already be weird enough for some astronomers.

They form in the cores of exploding stars. They defy Newtonian logic, and need Relativity to properly account for their gravity. They warp space and time. They power the most luminous single objects in the Universe. They don’t just pull you down, they spaghettify you first.

What kickstarted the birth of our solar system?

We know that the solar system formed from a collapsing cloud of cold gas and dust, called the protosolar molecular cloud, what was likely part of a much larger nebula. That’s been a working hypothesis for a long time, but over the past few decades we’ve actually seen many such collapsing clouds in nearby star-forming nebulae.

Just how massive can stars get? Maybe not *quite* as massive as we thought

Massive stars — I mean truly massive, with 20 or more times the Sun’s mass — are terrifyingly powerful. 

The energy they produce scales steeply with mass, so at the top end of this range stars can blast out so much light they can be seen in other galaxies with small telescopes, and would cook any planets they have to a crisp. They can light up entire nebulae, and when they explode at the ends of their short, violent lives they can outshine entire galaxies. Galaxies plural. 

Another black hole first: Astronomers capture a ring of light as photons orbit M87A*

In 2019, astronomers revealed the first ever close-up image of material swirling around a black hole. It was a staggering achievement, combining the power of many radio telescopes across Earth to make a virtual one — called the Event Horizon Telescope — the size of our planet.

NASA’s SLS rocket is now ready for its August 29 Moon launch

NASA is ready to return to the Moon.

After years of delays, cost overruns, technical problems, and political issues, the Artemis I mission to orbit the Moon has crossed its last t and dotted its last i. It could launch as soon as Aug. 29.

Betelgeuse aftermath: Still recovering from blowing its stack

In late 2019 and early 2020, Betelgeuse blew its top.

Literally. 

Around that time the famous bright star marking the right shoulder of Orion suddenly started dimming, dropping to about half its usual brightness. I still remember going outside and staring wide-eyed in awe of the star; it was substantially dimmer even by eye. 

Over time, some stars get uncomfortably close to the Sun

The Sun, like every star in the Milky Way, orbits the center of our galaxy. But they don’t all move in the same direction or at the same speed, and that means, over time, some stars pass the Sun in their galactic paths. 

And some come pretty close to us.

Astronomers find dark matter from 12 billion years ago

We know dark matter exists — a mysterious substance that is five times as prevalent in the Universe by mass as what we think of as “normal” matter, the stuff you and I and everything we see are made of. We see its effects through its gravity, even though we don’t know what it’s made of yet. Dark matter affects how galaxies rotate, and how they move in gigantic galaxy clusters. 

Radioactivity powers volcanoes of salty ice on Ceres

Ceres is the largest object in the asteroid belt, the wide expanse between Mars and Jupiter littered with debris left over from the solar system’s planet-making process. Ceres used to be called an asteroid, but is so large — over 900 kilometers in diameter — that planetary scientists now call it a protoplanet, meaning it was on its way to becoming an actual planet until the raw materials it was growing from ran out.