Philip Plait's Blog, page 21

I swear these illusions aren't moving. Your brain will say otherwise.

Y'all know how much I love illusions and what they tell us about the way our brains are wired. I have one for you that's really good, but I feel I should warn you: It might make you a little nauseated; it gives an illusory sense of motion to fixed patterns. I did quite a bit of reading for this and looked at a lot of versions of it, and afterwards felt decently queasy. Mind you I'm sensitive to motion sickness (reading in a car makes me feel seriously ooky), but on the other hand I was having si...

Can you build a satellite made out of… wood?

Before the end of year, two different groups from two different countries expect to launch extremely unusual but similar experiments into space. These experiments — and I can't believe I'm writing this — will test to see how well wood works as a structural component for satellites.

Yes, wood. Like, from trees.

I'll admit to being skeptical this will work, but both ideas are pretty interesting, and if they do pan out it could change the way some satellites are made.

One group is from Japan's K...

An ancient space object is fast, faint, and there may be billions more like it

A very odd object has been found zipping through the galaxy on a path relatively near to the Sun, and while nothing quite like it has ever been seen before, it may be the first of many such old, cold things prevalent in the Milky Way.

The object is called WISEA J153429.75−104303.3 (WISE is the Wide-field Infrared Survey Explorer space observatory, and the numbers are its coordinates on the sky; let’s call it WISE 1534 for short). Its discovery is a story all by itself: It was found by citizen s...

Counting boulders on tiny worlds tells us how ancient and fragile they are

Astronomy rocks!

Well, planetary science rocks. Literally.

Let’s explore two small worlds, each similar yet wildly different to the other, but both with a bolder tale to tell. Or a boulder one.

We’ll start with Ceres, the largest object in the main asteroid belt between Mars and Jupiter, and so big it was well on its way to becoming a true planet before it ran out of building material billions of years ago. For that reason, scientists call it a protoplanet. 

The Dawn spacecraft entered orbit...

Hubble spies a quintuple quasar… except it's a cosmic mirage

Peering across the Universe is hard. Happily, the Universe sometimes provides a little help, using gravity to give light a swift kick in the photons.

I'm talking about gravitational lensing:

Briefly, gravitational lensing is when the gravity of a massive object — a star, a black hole, a galaxy — bends space around it, causing light passing by to curve, like a car following the curve of a road. Einstein [wrote about this in relation to his work on Relativity], saying that matter bends space and...

An immense volcanic eruption in 1257 A.D. affected our entire planet. But which volcano exploded?

A titanic volcanic eruption in 1257 A.D. spewed out colossal amounts of ash, sulfur, and glassy pumice, and affected climate over the entire planet. It was one of the largest if not the largest eruption in the past 7,000 years, and evidence of it can literally be found from pole to pole.

But... what volcano erupted?

Weirdly, until recently no one knew just which volcano on Earth had exploded. This had geologists scratching their heads until just a few years ago, when multiple lines of evidence...

Beautifully dying stars and the scale of the Universe

What can dying stars tell us about the size and age of the Universe?

Possibly a lot, if a new technique developed by astronomers can be used routinely. It looks in other galaxies for stars like the Sun but which are at the ends of their lives, and from that determine how far away they are. This method has been used before, but what’s new here is a refinement that allows it to more accurately measure their brightness, and also go deeper. Much deeper, looking at galaxies that are over 120 million...

Want to find Planet Nine? Here's a treasure map.

Do you want to be the first person in 175 years to discover a new planet in our solar system?

Just follow the map.

Well, it’s not all that easy. You’ll need a huge telescope, lots of time, and at least some understanding of what you’re looking for and why. Let me help.

For the past twenty years or so a growing number of astronomers think that there may be another large planet in our solar system well beyond Neptune. Nicknamed Planet Nine*, its existence is inferred from the behavior of a grou...

Meet 2021 PH27, a newly discovered asteroid with the shortest known year!

Astronomers have discovered a new and odd asteroid: Called 2021 PH27, it orbits the Sun on the shortest orbit ever seen for any asteroid, taking it closer to the Sun than Mercury and only a little bit farther out than Venus!

It gets within a mere 20 million kilometers from the Sun at closest approach, which is less than 1/7th the Earth’s distance, and less than half Mercury’s closest solar distance. At farthest on its elliptical path it gets about 118 million km from the Sun.

Astronomers chara...

Why did this comet disintegrate when its sibling was able to hold it together?

On December 28, 2019, a new comet was discovered by ATLAS (the Asteroid Terrestrial-impact Last Alert System). Called C/2019 Y4 (ATLAS) — let's call it 2019 Y4 for short — it had an orbit that brought it to within about 38 million kilometers of the Sun, which is inside Mercury's orbit. Pretty close to the Sun.

In February 2020 the comet brightened rapidly, raising hopes it might become naked eye visible, but about a month later it became clear the opposite was going to happen: 2019 Y4 was disin...