Space and astronomy news
Meteorites strike Earth every day. It’s estimated that about 100 – 300 metric tonnes of material strike our planet every year. Most of it consists of sand-grain sized dust that burns up in the atmosphere, but each year a few thousand will reach Earth’s surface.
Continue reading “Most Mars Meteorites Came From Five Craters”
Yesterday the Sun released a huge solar flare, and it’s heading toward Earth! It’s nothing to worry about since it’s nowhere near as large as the Carrington Event of 1859, but it is large enough to give us some amazing aurora.
Continue reading “The Sun Unleashes its Strongest Flare This Cycle”
We’ve known the Universe is expanding for a long time. The first solid paper demonstrating cosmic expansion was published by Edwin Hubble in 1929, based on observations made by Vesto Slipher, Milton Humason, and Henrietta Leavitt. Because of this, the rate of cosmic expansion is known as the Hubble constant, or Hubble parameter, H0. From this parameter, you can calculate things such as the age of the Universe since the Big Bang, so knowing the value of H0 is central to our understanding of modern cosmology.
Continue reading “Gravitational Lens Confirms the Hubble Tension”
The thing about exoplanets is that astronomers don’t see them the way most people think they do. Part of the reason for that is the way we announce them. Whenever an interesting exoplanet is discovered, the press release usually has colorful artwork showing oceans, mountains, and clouds. Something visually captivating like the image above. But the reality is that we have only imaged a few exoplanets directly, and even then, they appear only as small fuzzy blobs. Most of the known exoplanets were discovered by the transit method, where the star dims slightly as the planet passes in front of it. So what astronomers actually see is a periodic flickering of starlight.
Continue reading “Bernard's Star Has a Planet (Again)!”
The Milky Way is special because it is our home. No matter where we are on Earth we can see its arc of light overhead if the night is dark enough. But how similar is our galaxy to others? Is it an unusual spiral galaxy, or is it rather typical in the cosmos?
Continue reading “How Does the Milky Way Compare to Other Galaxies?”
Ages ago in its youth, Mars appeared much like Earth. It was a warm planet with lakes, rivers, and vast seas. It had a thick atmosphere with clouds and rain. One major difference is that the atmosphere was rich with carbon dioxide instead of oxygen. Then about 3.5 billion years ago much of the atmosphere disappeared, and we haven’t understood how. A new study in Science Advances suggests that the waters of Mars may have been the key, and much of the ancient atmosphere may be locked in the surface of the red planet.
Continue reading “Martian Clay Could Be Hiding the Planet's Atmosphere”
The reason we call dark matter dark isn’t because it’s some shadowy material. It’s because dark matter doesn’t interact with light. The difference is subtle, but important. Regular matter can be dark because it absorbs light. It’s why, for example, we can see the shadow of molecular clouds against the scattered stars of the Milky Way. This is possible because light and matter have a way to connect. Light is an electromagnetic wave, and atoms contain electrically charged electrons and protons, so matter can emit, absorb and scatter light. Dark matter isn’t electrically charged. It has no way to connect with light, and so when light and dark matter meet up they simply pass through each other.
Continue reading “Dark Matter Could a Have Slight Interaction With Regular Matter”
The most likely way we will discover life on a distant exoplanet is by discovering a biosignature. This can be done by looking at the atmospheric spectra of a world to discover the spectral pattern of a molecule that can only be created through biological processes. While it sounds straightforward it isn’t. The presence of simple molecules such as water and oxygen don’t prove life exists on a planet. It’s true that Earth’s atmosphere is oxygen rich thanks to life, but geological activity can also produce large quantities of oxygen. And as a new study shows, some molecules we’ve long thought to be biological in origin may not be.
Continue reading “Biosignatures Can be Made in the Lab. No Life Needed.”
If there really are advanced alien civilizations out there, you’d think they’d be easy to find. A truly powerful alien race would stride like gods among the cosmos, creating star-sized or galaxy-sized feats of engineering. So rather than analyzing exoplanet spectra or listening for faint radio messages, why not look for the remnants of celestial builds, something too large and unusual to occur naturally?
Continue reading “Those Aren't Dyson Spheres, They're HotDOGs”
When you get close to a black hole, things can get pretty intense. The tremendous gravity can squeeze gas to ionizing temperatures, and fierce magnetic fields can accelerate plasma into jets speeding at nearly the speed of light. That’s a lot of power, and wherever there is power someone will figure out how to harness it.
Continue reading “Researchers Mimic Extracting Energy From Black Holes in the Lab”