Earth is made up of two planets fused together, new research suggests
RIP, planet buddy.
By Fiona MacDonald

Astronomers investigating how the Moon formed have found evidence that it was produced after a small planet smashed headfirst into Earth around 4.5 billion years ago. And research suggests that this collision was so violent that the ‘planetary embryo’ that hit us, called Theia, ended up fusing with both Earth and the Moon as a result.

The idea that the Moon was formed as part of a Solar System crash isn’t new, but scientists in the past have proposed that Theia simply side-swiped Earth, blasting the Moon into orbit and then continuing off into space. Now new research by a team at the University of California, Los Angeles, suggests that Theia actually never left us.

Continue Reading.


Atlas of Peculiar Galaxies

Here are some fun and unusual galaxies from the Atlas of Peculiar Galaxies, a catalog produced by Halton Arp. A total of 338 galaxies are presented in the atlas, which was originally published in 1966.

1. IC 883 (Arp 193), remnant of two galaxies’ merger    
2. Arp 147, an interacting pair of ring galaxies
3. Giant elliptical galaxy NGC 1316
4. Interacting pair of galaxies: Arp 238 (UGC 8335
5. Merging galaxy pair named NGC 520 (Arp 157)


We hear you’re all pretty bummed about the end of Astronomy, so our friends @thought-cafe worked with Phil to create one more awesome treat for you guys and we’re super excited to share it on the Crash Course channel. I highly recommend watching it in full screen at the highest resolution your system can handle. (Worth the wait to let it load, I promise!)

Take a 360 degree virtual tour of our Solar System, with the help of Crash Course Astronomy host Phil Plait!

Subscribe to Thought Café’s channel:

This video is part of Thought Café +, a collaborative animated series from the team behind the Crash Course animations!
Check out more of their videos here:

For the most immersive #360Video experience use Cardboard ( with the YouTube Android app. If you do not have Cardboard, you can use the YouTube apps for Android or iOS and move your mobile device to look around the solar system. On a desktop computer, use the latest versions of Chrome, Firefox, Internet Explorer, or Opera browsers to click and drag your mouse and follow along as we explore our Solar System.

As you’ve probably heard by now, gravitational waves have been detected for the first time by the Laser Interferometer Gravitational-Wave Observatory (LIGO). This is a momentous occasion for physics, as it experimentally confirms a result of Einstein’s Theory of Relativity that was considered almost impossible to verify. And while gravitational waves may not be sound, there’s still a strong connection to acoustics. LIGO itself has been described as a “Gravity Microphone” measuring the motion of spacetime, and the way the observatory works is not too far off from a Laser Doppler Vibrometer, using the change in travel time of a laser to measure passing waves. And LIGO’s executive director, David Reitze, said at a press conference for this announcement that “…Up until now we’ve been deaf to gravitational waves, but today we’re able to hear them.” What’s more, you can even hear an auralization of the measurement, shifted away from it’s original frequency range of 35 to 250 Hz. After listening to that recording I would say that our first measurement of gravitational waves sounds like a drop falling into a pond, appropriate for something sending ripples through science! (Image credit National Science Foundation Article. Article credit LIGO)


NASA Astronomy Picture of the Day 2016 February 12 

Two Black Holes Merge 

Just press play to watch two black holes merge. Inspired by the first direct detection of gravitational waves by LIGO, this simulation video plays in slow motion but would take about one third of a second if run in real time. Set on a cosmic stage the black holes are posed in front of stars, gas, and dust. Their extreme gravity lenses the light from behind them into Einstein rings as they spiral closer and finally merge into one. The otherwise invisible gravitational waves generated as the massive objects rapidly coalesce cause the visible image to ripple and slosh both inside and outside the Einstein rings even after the black holes have merged. 

Dubbed GW150914, the gravitational waves detected by LIGO are consistent with the merger of 36 and 29 solar mass black holes at a distance of 1.3 billion light-years. The final, single black hole has 62 times the mass of the Sun, with the remaining 3 solar masses converted into energy in gravitational waves.

Geminid Meteors over Xinglong Observatory : Where do Geminid meteors come from? In terms of location on the sky, as the featured image composite beautifully demonstrates, the sand-sized bits of rock that create the streaks of the Geminid Meteor Shower appear to flow out from the constellation of Gemini. In terms of parent body, Solar System trajectories point to the asteroid 3200 Phaethon – but this results in a bit of a mystery since that unusual object appears mostly dormant. Perhaps, 3200 Phaethon undergoes greater dust-liberating events than we know, but even if so, exactly what happens and why remains a riddle. Peaking last week, over 50 meteors including a bright fireball were captured streaking above Xinglong Observatory in China. Since the Geminids of December are one of the most predictable and active meteor showers, investigations into details of its origin are likely to continue. via NASA


Gravitational waves exist. Yesterday, scientists from the Laser Interferometer Gravitational-Wave Observatory (LIGO) made one of the most important scientific breakthroughs in modern times. They confirmed, for the first time, the existence of gravitational waves. Ripples in the fabric of spacetime, they were first predicted by Albert Einstein in 1916, but a century passed before their existence could be confirmed.

The confirmation of their existence opens up an entirely new field of astrophysics and gives scientists another tool in their attempts to fully understand the Universe. For example, the readings of gravitational waves will possibly allow us to look back into the first 40,000 years of the Universe’s creation, a period of time we currently know very little about.

In celebration of this momentous discovery, we’ve pulled together a list of freely-available articles below:

Image: “This visualization shows what Einstein envisioned. Researchers crunched Einstein’s theory of general relativity on the Columbia supercomputer at the NASA Ames Research Center to create a three-dimensional simulation of merging black holes. This was the largest astrophysical calculation ever performed on a NASA supercomputer. The simulation provides the foundation to explore the universe in an entirely new way, through the detection of gravitational waves.” Image by Henze, NASA. Public Domain via Wikimedia Commons.