Philip Plait's Blog, page 30

Hubble sees a nearby very young exoplanet finishing up a growth spurt

For the first time, astronomers have obtained a direct image of a young, still-forming exoplanet in ultraviolet light, allowing them to measure just how fast it's growing. The number is surprisingly low, meaning the planet may be at the tail end of its growth spurt.

PDS 70 is a very young star, only about 5 million years old (the Sun is a thousand times older than that), located 370 light years away in the constellation of Centaurus. In the early 2000s astronomers determined PDS 70 was still su...

Dating craters: Wolfe Creek is younger, Meteor Crater older, than previously thought

How old are impact craters on Earth?

This is a hard question to answer, for a lot of reasons. For one thing, big impacts are rare, so craters don't get made very often. That's a good thing! But it means we don't have lots of examples, so it can be difficult to work with them.

For another, Earth is an active planet. Air, water, tectonics... these are all sources of erosion, and after a few hundred thousand — or hundred million — years, craters fade away. If it weren't for those factors, the sur...

A star that lived, then died, then lived again, then died for real

Abell 78 is a lovely planetary nebula about 4,500 light years from Earth. Like all of its kind, it was formed when a star similar to the Sun started dying.

It ran out of nuclear fuel in its core, swelled up into a red giant, and started blowing away its gaseous outer layers into a cloud around it. As deeper parts of the star were exposed, a faster wind blew, catching up with and slamming into the older, slower wind. Eventually the core of the star was all that was left: a hot, dense object call...

The 3D heart of the Crab Nebula

Astronomers have done something very cool: Made a 3D map of the expanding debris from the supernova explosion that created the Crab Nebula, one of the closest and brightest such supernova remnants in the sky.

By creating a model of the 3D shape, it's possible to virtually observe the nebula from any direction, and to their surprise the astronomers found it's not an ellipsoid (like a the shape of an American football) as thought, but actually shaped like a heart. In this case I mean a cardioid, ...

For its birthday, Hubble has cake with several octillion tons of flaming candles on it

On April 24, 1990, the Space Shuttle orbiter Discovery thundered into orbit. A day later, clamped in the grip of the robotic Canadarm, the Hubble Space Telescope was pulled out of the orbiter's payload bay and then set free to orbit the Earth.

That was 31 years ago this past weekend. Since then, Hubble has looked at everything from the Moon (and even, technically, the Earth) to almost literally the edge of the observable Universe, 13+ billion light years away.

Anticipating the anniversary, ear...

Millions of lonely black holes are in our galaxy. Here’s how we’ll find some of them.

How many black holes are there in our galaxy?

We don't know. But we can make a decent guess: We know the kinds of stars that make black holes (massive stars that explode at the ends of their lives), we know how many of those kinds of stars are born over time, and we know how old the galaxy is.

Putting that all together and doing the math, you get that the galaxy may have ten million black holes in it. Yikes.

…but that number is so uncertain there could be as many as a billion of them, too. A ...

In a technological first, NASA has made a sip of breathable air on Mars

Well, isn't this a breath of fresh air: An experiment on board the Mars Perseverance rover designed to produce breathable oxygen from carbon dioxide has been switched on and is working! On April 20 it produced 5 grams of oxygen — not a huge amount, but it's designed to make as much as 10 grams per hour, and this is the very first time oxygen has been converted from native air on another planet.

The device is called MOXIE — the Mars Oxygen In-Situ Resource Utilization Experiment — and it's small...

Astronomers find an exoplanet where an exoplanet shouldn’t be

Over 4,000 exoplanets — alien planets orbiting other stars — have been found by astronomers so far.

There are a variety of ways to find them, most of which use indirect methods, but one of the coolest is quite direct: Getting actual images of the planets near their host stars. Called direct imaging, this technique has been used to find dozens of planets.

A team of astronomers has targeted 70 nearby stars to look for such exoplanets, and have just announced a new one: YSES 2b, a giant planet or...

Watch the doubly warped view of two monster black holes orbiting each other

Mostly, supermassive black holes like to live alone.

Sitting in the centers of all big galaxies, these monsters outweigh our Sun by a factor of millions, even billions. They chow down on stars, gas, dust, whatever unwary material gets too close.

Finding a second supermassive black hole close to the first one is rare. We've seen a few (and they should have been more common when the Universe was young), but they're not easy to spot.

Still, say they were… and say we could hop aboard the Enterpri...

Mars Ingenuity takes flight! Watch the first out-of-this-world video

Today, NASA made interplanetary history: The Mars helicopter Ingenuity made the first powered, controlled flight off the surface and into the air on another world.

At 07:34 UTC (3:34 Eastern US time) — just after noon local time on Mars — the twin-bladed drone made a vertical test flight, going 3 meters above the ochre Martian dust, hovered stably for 30 seconds, and then landed once again. Nothing like this has ever been attempted before on another planet, and it’s the harbinger of many more s...