from the world's big
Astrophysicist Michelle Thaller talks ISS and why NICER is so important.
- Being outside of Earth's atmosphere while also being able to look down on the planet is both a challenge and a unique benefit for astronauts conducting important and innovative experiments aboard the International Space Station.
- NASA astrophysicist Michelle Thaller explains why one such project, known as NICER (Neutron star Interior Composition Explorer), is "one of the most amazing discoveries of the last year."
- Researchers used x-ray light data from NICER to map the surface of neutrons (the spinning remnants of dead stars 10-50 times the mass of our sun). Thaller explains how this data can be used to create a clock more accurate than any on Earth, as well as a GPS device that can be used anywhere in the galaxy.
You think you've had a day where everything that went wrong could? T-Rex has you beat.
- A new study suggests that the object that brought about the end of the dinosaurs crashed into the Earth at a 60-degree angle.
- This is about the worst possible angle for such an impact.
- The findings also help explain the nature of the impact crater in Yucatan.
Talk about bad luck<p>The angle of an asteroid impact can have effects on the aftermath every bit as dramatic as increasing or decreasing the size of the asteroid itself.</p><p>According to the findings of this study, the asteroid struck Earth at around sixty degrees. At that angle, the amount of climate-changing gas released by the impact is up to three times higher than the amount released by an impact at a lower one. The result of this was a global impact winter that doomed the dinosaurs and took a fair amount of other plant and animal life down with them.</p><p>Had it struck at a lower angle, the force of the impact would have been dispersed more widely in more shallow layers of rock, sending fewer gasses into the air. A review of most craters suggests that impactors tend to come in at low angles. The odds of one coming in at sixty degrees or above is just one in four. </p><p>This was made worse by the location, just off the coast of what is now Yucatan. Gypsum deposits at the impact site would have released vast amounts of sulfur gas into the atmosphere, as described above. If the impact site had been somewhere else with a different geological makeup, fewer climate-altering gasses would have been released by the impact.</p><p>Sometimes, you just can't win. </p><p>The result of this perfect storm of high impact angle and sulfate laden location was apocalyptic. The impactor, assumed in this study to be a 12 kilometers (7 miles) wide asteroid made of granite, slammed into the Earth at terminal velocity. It blew a hole in the crust perhaps 30 kilometers (19 miles) deep, and sent up mountains of fluidized rocks to rival the Himalayas before they collapsed.</p><p>Endless supplies of vaporized sulfur were released into the atmosphere, severely reducing the amount of solar radiation reaching the Earth. Some estimates suggest this was severe enough to make photosynthesis impossible.</p>
How do we know all this? I mean, it was 65 million years ago, and the dinosaurs didn't leave notes.<div class="rm-shortcode" data-media_id="40V32ZfH" data-player_id="FvQKszTI" data-rm-shortcode-id="4e712374fd3a1866130f285a8739c36d"> <div id="botr_40V32ZfH_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/40V32ZfH-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/40V32ZfH-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/40V32ZfH-FvQKszTI.js"></script> </div> <p>We do know what the impact crater looks like; you can see it for yourself in the Yucatan. The part that is on land is known for its <a href="https://en.wikipedia.org/wiki/Cenote#Chicxulub_Crater" target="_blank">sinkholes</a>, which map out the impact site. If you know that you can model a variety of scenarios and compare them to the conditions we see. If they match, we have a winner. This is what the scientists did.</p><p> Professor Collins of the Imperial College of London and the lead author of this study explained the <a href="https://www.bbc.com/news/science-environment-52795929?at_custom3=BBC+News&at_custom2=facebook_page&at_medium=custom7&at_campaign=64&at_custom1=%5Bpost+type%5D&at_custom4=18FA6412-9F68-11EA-AE4E-2604C38169F1&fbclid=IwAR22ZXtvAyCwXoYshAzC5qPSMqOYzBGQaEYPSYKS8uMWim8SnCC8yMxKRSY" target="_blank">results</a>: "If you run the model at different impact angles, at 30 degrees and at 45 degrees, say, you can't match the observations - you get centres of mantle uplift and of the peak ring on the downrange side of the crater centre. And for a straight overhead impact, at 90 degrees, the centres are all on top of each other. So, that's doesn't match the observations, either."</p><p>As a result, we know that if the angle of impact was flatter it would have produced different effects, and the people reading this might be advanced dinosaurs rather than intelligent apes. Likewise, Yucatan might not have its famous, beautiful sinkholes. </p><p>Now that would be a tragedy. </p>
The planet that we are searching for is a little bit smaller and closer than we originally thought.
- Years ago, California Institute of Technology professor Konstantin Batygin was inspired to embark on a journey of discovering what lurked beyond Neptune. What he and his collaborator discovered was a strange field of debris.
- This field of debris exhibited a clustering of orbits, and something was keeping these orbits confined. The only plausible source would be the gravitational pull of an extra planet—Planet Nine.
- While Planet Nine hasn't been found directly, the pieces of the puzzle are coming together. And Batygin is confident we'll return to a nine-planet solar system within the next decade.
MIT engineers devise a decision map to identify the best mission type to deflect an incoming asteroid.
On April 13, 2029, an icy chunk of space rock, wider than the Eiffel Tower is tall, will streak by Earth at 30 kilometers per second, grazing the planet's sphere of geostationary satellites.
The object, originally dubbed "Ultima Thule," was renamed to "Arrokoth" due to the connection between the word "Thule" and the Nazis.
- When the New Horizons probe originally visited Arrokoth, the most distant celestial body to have ever been visited by a spacecraft, NASA researchers nicknamed the body "Ultima Thule."
- Thule refers to a distant mythological civilization. Although it originated in ancient Greek and Roman literature, the Nazis co-opted the term to refer to a mythological homeland of the Aryan people.
- The new name, Arrokoth, is Powhatan for "sky."
What's special about Arrokoth?<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjA5NjkwNi9vcmlnaW4uZ2lmIiwiZXhwaXJlc19hdCI6MTU5Nzk2NzIyMX0.rKa9BrqLA7ghm0U4j8pGLfSu0VDbfF01LAIeCSMetLg/img.gif?width=980" id="fc27d" class="rm-shortcode" data-rm-shortcode-id="88dc52ba8bfb4e56ed62a24ae08fd702" data-rm-shortcode-name="rebelmouse-image" alt="Ultima Thuler/Arrokoth" />
A 3D animation of Arrokoth.
NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute<p>As for Arrokoth itself, the object has a peculiar, snowman-like shape consisting of two small orbs measuring 14 miles and 9 miles across, respectively, which researchers believed were separate objects that crashed together at one point, possibly demonstrating how larger objects like planets initially form. The planetesimal appears to be covered in water ice, methanol, and <a href="https://bigthink.com/surprising-science/why-tholins-may-have-helped-life-begin" target="_self">tholins</a> — complex organic compounds resulting from cosmic radiation that give Arrokoth its rust-red color. It floats roughly 4 billion miles away from Earth in a region of our solar system known as the Kuiper belt, a massive disc of asteroids made of rock, metal, and frozen chemicals that envelops Pluto, New Horizons' original and primary target.</p><p>Arrokoth was selected to be visited by <a href="https://www.nasa.gov/feature/nasa-s-new-horizons-team-selects-potential-kuiper-belt-flyby-target" target="_blank">New Horizons</a> primarily due to fuel concerns and the possible scientific value of its observations. Fortunately, New Horizons will have enough power to operate until the 2030s and may even give another go at exploring distant Kuiper belt objects in the 2020s. No doubt the next object will be given a more thoroughly vetted name. </p>