Philip Plait's Blog, page 17

Half-eaten exoplanet entrails in zombie stars show how weird alien worlds are

We know lots of rocky worlds roughly similar to Earth are out there orbiting other stars. The problem with finding and learning about them is that they're small and faint and extremely difficult to observe.

So some astronomers came up with an idea borrowed from archaeologists: Find their gravesites and examine their remains.

Hubble portrait of a galaxy shows it shines in stellar birth and death

Three things I love to write about are gorgeous spiral galaxies, exploding stars, and astronomical mysteries.

This makes NGC 4666 a perfect target: It's certainly spectacular, a star blew up in it, and it's not clear why the detonated star's corpse behaved the way it.

What is causing galaxies in the Virgo Cluster to die?

Some galaxies die young.

A galaxy is an immense structure of stars, gas, dust, and dark matter, all held together by mutual gravity. Stars are typically the main source of visible light from galaxies, and in most galaxies we see stars are being born from clouds of gas and dust. That guarantees that those galaxies will still shine for many billions of years.

Where *isn't* Planet 9?

For a few years now, some astronomers have been looking for another planet in the solar system, one much larger than Earth that orbits the Sun far beyond Neptune. Not-so-tongue-in-cheekily, they've been calling it Planet 9.

The complex diversity of the gorgeous globular cluster M5

One of my favorite things about astronomy as a field of science is how, after enough evidence piles up about a topic, we can change our minds about it.

Globular clusters are a perfect example of this. Globulars are star clusters, containing hundreds of thousands or, for the biggest ones, even millions of stars all packed into a roughly spherical volume ranging from a couple of dozen to a couple of hundred light years across.

Why is the asteroid Bennu’s surface rocky and not smooth?

When the OSIRIS-REx spacecraft arrived at the tiny asteroid Bennu, scientists expected the wee world to look like a beach. Instead, it looked like a construction site.

Scientists now think they know why.

Juno digs into Jupiter and sees the Great Red Spot goes way deeper than thought

New results from the Jupiter-divebombing spacecraft Juno reveal more about the depths of the gigantic planet including just how voluminous the Great Red Spot is, weird info about its stripes, and more about the even weirder and eerily regular cyclones swarming at its poles.

Cancel Columbus Day: Sun storms pinpoint Europeans being in Canada in 1021 A.D.

New research pinpoints an exact date Vikings from Europe were in North America: 1021 A.D. (one millennium ago this year), 430 years before Christopher Columbus was even born.

How was this determination possible? Because the Sun erupted in an immense series of storms that altered Earth's atmosphere, leaving measurable changes in tree rings at the time.

In the 1960s, archaeologists discovered a Norse Viking site in L'Anse aux Meadows, in the northern tip of Newfoundland. By looking at the styles...

A single object ripped out over 1,600 Fast Radio Bursts in just a few days and no one knows why

Let's cut right to the chase, shall we? No one knows what causes Fast Radio Bursts, intense but extremely short blasts of radio waves. By "intense" I mean pouring out possibly millions of times the energy the Sun does, and by "short" I mean short: they literally last a millisecond or so. A thousandth of a second.

The first ones detected (in the early 2000s) were one-and-done, flashing once and then disappearing. A breakthrough occurred in 2016 when a Fast Radio Burst (or FRB) that went off firs...

Mercury's atmosphere thickened as we watched. The likely perp? Meteoroids.

Mercury is the smallest planet in the solar system. It’s a ball of rock and metal just under 5,000 kilometers across (about 40% wider than our Moon), and the closest planet to the Sun. That means it’s hot, of course, with a surface temperature that reaches well over 400° C (750° F). Lead melts at 327°C, by the way.

It’s common to describe Mercury as airless, lacking an atmosphere, and that’s true, more or less… though more less than more. It doesn’t have an atmosphere per se, but it does have a...