Black holes are the largest single objects in the universe, many times larger than even the biggest stars, and have no upper limit to their size. But practically, how big is the biggest, heaviest black hole in the universe? (A: More massive than the entire Milky Way.)
The largest things in the universe are black holes. In contrast to things like planets or stars they have no physical size limit, and can literally grow endlessly. Although in reality specific things need to happen to create different kinds of black holes, from really tiny ones to the largest single things in the universe. So how do black holes grow and how large is the largest of them all?
Videos about space are where Kurzgesagt really shines. I’ve seen all their videos about black holes and related objects, and I always pick up something I never knew whenever a new one comes out. This time around, it was quasistars and the surprisingly small mass of supermassive black holes located at galactic centers compared to the galaxies themselves.
In this collaboration between musician and filmmaker John Boswell (aka melodysheep) and the sound podcast Twenty Thousand Hertz, we get to listen to some of the actual and theoretical sounds of space, from what the Sun would sound like if space weren’t a vacuum (we’d hear it as loud as a jackhammer on Earth) to the sound of the Universe just after the Big Bang to thunder in the thick atmosphere of Venus to dreamlike piano music on Mars.
Floating in the silent void of space are trillions of islands of sound, each with their own sonic flavor — some eerily familiar, some wildly different than Earth’s. And even space itself was once brimming with sound.
This short film takes you on a journey back in time and to the edge of our solar system and beyond, to discover what other worlds of sound are lurking beyond Earth’s atmosphere. You won’t believe your ears :)
After Neil Armstrong and Buzz Aldrin landed on the Moon 52 years ago today in the Lunar Module (aka Eagle), they rode the ascent stage of the LM back to rendezvous with Michael Collins in the Command Module (aka Columbia). After docking, Eagle was jettisoned and the three astronauts returned to Earth in Columbia. It was presumed that Eagle orbited the Moon until eventually crashing into the surface, but a recent analysis shows that the spacecraft may have entered a stable orbit and is still circling the Moon decades after the end of the mission, a priceless artifact of an historic achievement.
Most spacecraft in lunar orbit suffer from instability in their orbits due to the ‘lumpy’ nature of the lunar gravity which tends to cause the orbits to eventually get so elliptical that they hit the moon.
However, an amateur space fan wanted to narrow down the possible impact location and used orbit modelling software to propagate the orbit forwards in time until it hit the moon. He was surprised to find that it didn’t hit the moon, and remained in a stable orbit for decades, this suggests that the Eagle may still be orbiting the moon over 5 decades after being left there.
The paper detailing the analysis suggests that if Eagle has survived, it should be detectable by radar.
The galaxy is wild. Our solar system, with its surprising abundance of living creatures and nonstop radiation and asteroid showers, is a placid, private garden compared to the rest of it.
In particular, there are perhaps trillions of rogue planets (planetary bodies ranging from little rocky Earth-sized guys to super-Jupiter gas giants) in the Milky Way, including a surprisingly large fleet of the things right near the galactic core.
This is unusual, since the typical way we detect exoplanets is by marking their repeated procession across a star. But rogue planets, by definition, don’t orbit stars. So the way astronomers find them is a little different, requiring use of gravitational microlensing.
Data gathered by NASA’s now-retired Kepler Space Telescope has revealed a small population of free-floating planets near the Galactic Bulge. The new finding raises hope that a pair of upcoming missions will result in further detections of unbound planets, which drift through space separated from their home stars….
It’s impossible to know what the conditions are like on these presumed rogue exoplanets, but [astronomer Iain] McDonald said they could be “cold, icy wastelands,” and, if similar in size to Earth, their surfaces would “closely resemble bodies in the outer Solar System, like Pluto.”
The new paper suggests the presence of a large population of Earth-sized rogue planets in the Milky Way. It’s becoming clear that free-floating planets are common. McDonald said his team is currently working to come up with a more precise estimate for how many of them might exist.
Did you catch that part about how McDonald’s team made this discovery using a now-retired telescope? Yeah. Apparently the new telescope projects coming online are both more powerful and (in particular) better equipped to detect gravitational lensing effects, and therefore more likely to detect rogue planets in the future.
And it turns out, astronomers are about to witness the closest pass of this incredible round trip. Currently, 2014 UN271 is about 22 Astronomical Units (AU) from the Sun (for reference, Earth is 1 AU from the Sun). That means it’s already closer than Neptune, at 29.7 AU. And it’s not stopping there — it’s already traveled 7 AU in the last seven years, and at its closest in 2031, it’s expected to pass within 10.9 AU of the Sun, almost reaching the orbit of Saturn.
Before then, it’s expected to develop the characteristic coma and tail of a comet, as icy material on its surface vaporizes from the heat of the Sun. This close pass would give astronomers an unprecedented close look at Oort cloud objects.
C’mon NASA, let’s a get a probe fired up and visit this very unusual object!
In the history of science, there are women who have made significant contributions to their field but haven’t gotten the recognition that their male peers have. The field of astronomy & astrophysics in particular has had many female pioneers — Vera Rubin, Cecilia Payne-Gaposchkin, Annie Jump Cannon, Nancy Grace Roman, Maria Mitchell, Jocelyn Bell Burnell, Henrietta Swan Leavitt, Caroline Herschel, Williamina Fleming, and many others. Add to that list Hisako Koyama, a Japanese astronomer whose detailed sketches of the Sun over a 40-year period laid the foundation for a 400-year timeline of sunspot activity, which has aided researchers in studying solar cycles and magnetic fields.
Ms. Koyama was a most unusual woman of her time. As a scientist, she bridged the amateur and professional world. She preferred “doing” activities: observing, data recording, interacting with the public, and writing. No doubt many Japanese citizens benefited from personal interaction with her. The space and geophysics community continues to benefit from her regular and precise observations of the Sun. Although we know very little of her young personal life other than she was relatively well educated and had a father who supported her desire to view the skies by providing a telescope, we can see from snippets in Japanese amateur astronomy articles that she had a passion for observing, as revealed in her 1981 article: “I simply can’t stop observing when thinking that one can never know when the nature will show us something unusual.”
Here are a few of her sunspot sketches, the top two done using her home telescope and the bottom one using the much larger telescope at the National Museum of Nature and Science (that shows the largest sunspot of the 20th century):
This is a photo of a tiny tiny snippet of the universe, taken by the Hubble Space Telescope. Every object you see in the photo is a staggeringly massive galaxy that contains hundreds of billions of stars along with all sort of other things.
Our own galaxy, the Milky Way, is well over one hundred thousand light years across. We only see a pitiful portion of it. Although it contains several hundred billion stars in its expanse, we can only see a fraction of a fraction of them.
And even that doesn’t fully capture the essence of a galaxy, which also has planets, gas, dust, dark matter, and more. Galaxies are colossal objects, their true nature only becoming apparent to us a century ago.
I know I’ve posted photos like this before, but every time I see something like this, my mind boggles anew at the sheer scale and magnitude of it all and I just have to share it.
P.S. And Earth contains the only sentient life in the entire universe? Lol.
The cosmos is a swirling soup of stardust. Every day, approximately 60 tons of dust from asteroids, comets, and other celestial bodies fall to the Earth. These tiny metallic, alien stones of various shapes, textures, and colors-known as micrometeorites-are some of the oldest pieces of matter in the solar system.
Even though micrometeorites blanket the Earth, scientists have generally only been able to discover them in remote places devoid of human presence, such as Antarctic ice, desolate deserts, and deep-sea sediments. Scientists began searching for micrometeorites in the 1960s, and they predominantly thought the extraterrestrial dust would be impossible to find in urban environments. The conventional wisdom held that densely populated areas had too much man-made sediment that camouflaged the tiny space particles.
But Jon Larsen, a Norwegian jazz musician and creator of Project Stardust, was able to show that it is possible to find micrometeorites in more populated areas. In a study published in January 2017 in the journal Geology, he and his colleagues catalogued more than 500 lustrous micrometeorites (and counting), all recovered from rooftops in urban areas.
Astrophotography enthusiast Andrew McCarthy took a 140-megapixel photo of the Sun yesterday and, gosh, the Sun is just so cool to look at. I don’t know if you can see it above, but there’s a little something hidden in the photo, a transiting ISS:
For his Earth Restored project, Toby Ord digitally remastered 50 photographs of the whole Earth taken by Apollo astronauts during their missions in the 60s and 70s.
The Apollo photographs are historic works of art. So in restoring them, I sought to bring out their own beauty. I refrained from recomposing the images by cropping, or trying to leave my own mark or interpretation. Perhaps in some cases this would make a more pleasing image, but it was not my aim.
And the Apollo photographs are also a scientific record of what our Earth looks like. In particular, what it would have looked like from the perspective of the astronaut taking the shot. So rather than pumping the saturation or adjusting the colours to what we think the Earth looks like, I wanted to allow us to learn from these photographs something about how it actually appears.
Many of these shots are new to me — the Apollo program and its scientific and cultural output continue to be revelatory 50 years later.
Update: Full resolution images are available when you click through on each photo. You may have to make your browser window wider to see the link. (thx, colin)
The solar-powered helicopter first became airborne at 3:34 a.m. EDT (12:34 a.m. PDT) — 12:33 Local Mean Solar Time (Mars time) — a time the Ingenuity team determined would have optimal energy and flight conditions. Altimeter data indicate Ingenuity climbed to its prescribed maximum altitude of 10 feet (3 meters) and maintained a stable hover for 30 seconds. It then descended, touching back down on the surface of Mars after logging a total of 39.1 seconds of flight. Additional details on the test are expected in upcoming downlinks.
Ingenuity’s initial flight demonstration was autonomous — piloted by onboard guidance, navigation, and control systems running algorithms developed by the team at JPL. Because data must be sent to and returned from the Red Planet over hundreds of millions of miles using orbiting satellites and NASA’s Deep Space Network, Ingenuity cannot be flown with a joystick, and its flight was not observable from Earth in real time.
NASA livestreamed the team in Mission Control as the test results were transmitted back to Earth. The photo above is of Ingenuity’s shadow taken while in flight by its onboard camera.
Last month I shared a video of the Earth rising over the surface of the Moon captured by Japan’s Kaguya orbiter. It’s a good clip but quite short and over-narrated. Seán Doran took several Earthrise & Earthset sequences filmed by Kaguya, remastered & upsampled them to 4K resolution, and stitched them together into this wonderful video, set to music by Jesse Gallagher. One of the sequences, which begins around the 5-minute mark, captures a solar eclipse of the Sun by the rising Earth. I hadn’t seen this footage before and had to pick my jaw up off the floor — absolutely spectacular.
Working with Dr. Heather Igloliorte at Montreal’s Concordia University, Inuit artist Jesse Tungilik and a group of students designed and built a spacesuit made out of seal skin. Tungilik was inspired by the feelings he’d had as a child, bundled up in hunting clothes made by his mother out of caribou hide.
When Jesse Tungilik was a child, his mother made him traditional caribou hunting clothes. While wearing the bulky, heavy handmade outfit, he often imagined that he was in a spacesuit.
“That memory stuck with me when I heard about this opportunity here at Concordia, with its future-themed focus, and the two ideas met in the middle,” Tungilik says.
The image above is a still from a video taken by Brittany Hobson of the spacesuit on display in an exhibition at the Qaumajuq museum in Winnipeg. She says “the video doesn’t do it justice” but the suit looks pretty amazing in that video — I would love to see this in person someday. Dr. Igloliorte, who co-curated the exhibition, talked about the suit and its creation in this video:
Via CBC, you can see a photo of Tungilik as a kid, bundled up in his homemade “spacesuit” while out hunting with his father. Aww. (via @UnlikelyWorlds)
NASA’s Earth Observatory is holding a single-elimination tournament to find the best photograph taken by an astronaut from the International Space Station. Round 2 is now underway, with 16 photos duking it out for the top spot. The winners are determined by public vote, so get in there and vote for your favorites! (via @thelastminute)
Captured by the Kaguya lunar orbiter on April 5, 2008, this is an HD video of the Earth rising over the surface of the Moon. Watching stuff like this always puts me in a different frame of mind. (Turn off the sound if you don’t want to hear the super-cheesy narration.)
NASA engineers encoded a secret message in the parachute the Perseverance rover used to slow its descent to the surface of Mars. Tanya Fish provided a handy guide to decoding it on Twitter and as a PDF available on GitHub.
Just a few days after the Perseverance rover successfully touched down on Mars, NASA has released onboard video from the descent and landing from multiple perspectives. I watched this with my kids last night and all three of us had our mouths hanging open.
The real footage in this video was captured by several cameras that are part of the rover’s entry, descent, and landing suite. The views include a camera looking down from the spacecraft’s descent stage (a kind of rocket-powered jet pack that helps fly the rover to its landing site), a camera on the rover looking up at the descent stage, a camera on the top of the aeroshell (a capsule protecting the rover) looking up at that parachute, and a camera on the bottom of the rover looking down at the Martian surface.
After watching it again just now, I am struck by two things:
Sometime in my lifetime, live broadcasts from Mars will likely become commonplace. There will be dozens or hundreds of Mars webcams you can pull up on whatever the 2052 internet equivalent is. It will be amazing how boring it all is. (Or perhaps it’ll be boring how amazing it all is.)
Today is the day! NASA’s latest Mars rover is scheduled to touch down on the surface of Mars at around 3:55pm EST today1 and you can follow along online. You probably know the drill by now: what you’ll be watching isn’t actually live (it’s delayed by 11 minutes & 22 seconds, the time it takes for data to reach the Earth from Mars) and there’s no video to watch…there’s just telemetry from the rover that indicates where it is and what it’s doing. But I can say having watched the Curiosity landing in 2012, it’s still super exciting and nerve-wracking.
All times in this post (and stated by NASA in their schedules) are when we here on Earth will learn of events after the 11 minute & 22 second informational travel time from Mars is factored in. So while the Mars landing will actually occur around 3:44pm EST, we won’t know about it until 3:55pm EST.↩
Curiosity is about to get some company. NASA’s newest rover, Perseverance, is set to land on Mars beginning tomorrow at around 3pm EST. The video above walks us through the 7-minute landing routine in which the rover ditches its spacecraft, heat shields its way through the Martian atmosphere, deploys its parachute, uses an onboard guidance system to navigate to a good landing spot, and finally is lowered down to the surface via a sky crane. The rover’s destination is Jezero Crater, site of an ancient river delta and lakebed.
Jezero Crater tells a story of the on-again, off-again nature of the wet past of Mars. More than 3.5 billion years ago, river channels spilled over the crater wall and created a lake. Scientists see evidence that water carried clay minerals from the surrounding area into the crater lake. Conceivably, microbial life could have lived in Jezero during one or more of these wet times. If so, signs of their remains might be found in lakebed or shoreline sediments. Scientists will study how the region formed and evolved, seek signs of past life, and collect samples of Mars rock and soil that might preserve these signs.
Here’s how you can watch the landing “live” tomorrow (i.e. delayed by the 11 minutes & 22 seconds it takes for signals to travel from Mars). I’ll do a separate post tomorrow w/ the proper YouTube embeds so we can all follow along together.
It’s the result of the DESI Legacy Imagining Surveys, maps of the sky made by the three observatories (the Dark Energy Camera Legacy Survey, the Beijing-Arizona Sky Survey, and the Mayall z-band Legacy Survey, in combination with the orbiting WISE infrared observatory). They mapped the northern sky in seven colors, covering a third of the entire sky — 14,000 square degrees, or the equivalent area of 70,000 full Moons on the sky.
The ultimate goal is to better understand dark energy, the mysterious substance that’s accelerating the expansion of the Universe, by looking at the distribution of galaxies throughout the Universe. They’ll do that by picking tens of millions of the billion galaxies in the data and getting follow-up observations with the Dark Energy Spectroscopic Instrument (DESI), which will take spectra of those galaxies and find their distances.
Since we’ll know their positions on the sky, and their distances, this will make a 3D map of the Universe larger than any ever before.
The photo included at the top of the post is just a tiny tiny bit of the full image — you can pan and zoom the whole thing in this viewer. Be sure to zoom out in increments from the default view so as to fully appreciate just how absurdly large this image (and the universe) is.
Using images from the Kaguya orbiter, Seán Doran has constructed a 4-hour realtime orbit of the Moon. Feel free to pair with your favorite piece of relaxing music for a meditative viewing experience.
Researchers at Kyoto University and a Japanese forestry company have joined forces to develop orbital satellites made out of wood, purportedly to address the growing threat of space junk. The design will need to be resistant to dramatic changes in temperature and sunlight but will easy burn up in the Earth’s atmosphere upon reentry.
I love the idea of satellites made from wood — it seems like Victorian-era scifi. The harshness of space seems like a domain exclusively for metals and ceramics, but wood is a surprisingly versatile material used in many different severe environments on Earth. There’s no reason it couldn’t work in space as well — and if their traditional expertise in joinery is any indication, I trust the Japanese to figure out a way make it happen.
Unfortunately, making satellite housings out of wood won’t help with this, for many, many reasons. To start with, a lot of the junk isn’t ex-satellites; it’s often the boosters and other hardware that got them to orbit in the first place. Housings are also only a fraction of the material in a satellite, leaving lots of additional junk untouched by the change, and any wood that’s robust enough to function as an effective satellite housing will be extremely dangerous if it impacts anything at orbital speeds.
Using the Dark Energy Camera at the Cerro Tololo observatory in Chile, astronomers took an image of the stars clustered around the center of our Milky Way galaxy that shows about 10 million stars. Check out the zoomable version for the full experience.
Looking at an image like this is always a bit of a brain-bender because a) 10 million is a huge number and b) the stars are so tightly packed into that image and yet c) that image shows just one tiny bit of our galactic center, d) our entire galaxy contains so many more stars than this (100-400 billion), and e) the Universe perhaps contains as many as 2 trillion galaxies. And if I’m remembering my college math correctly, 400 billion × 2 trillion = a metric crapload of stars. (via bad astronomy)
Even after all the images were shot and each panel completed, the finished image did not come together smoothly. “I began in 2015 on a Mac Pro with 2 Xeon Processors and 64GB of RAM. This machine was easily one of the fastest computers of the day, and it carried me all the way up to panel 47 where I believe I hit the RAM limit of the computer.”
It would take five years from that point for technology to catch up to Harbison’s needs as he wouldn’t have a computer powerful enough to complete the task until August of 2020. “The new computer is an AMD Threadripper with 24 cores and 256GB of memory,” Harbison said. “It took a total of 23 hours to provide an astrometric solution for all 200 panels and then an additional 19 hours to merge into the gradient merge mosaic tool.”
What an amazing thing to be able to make from your backyard.
The Origins Spectral Interpretation Resource Identification Security - Regolith Explorer spacecraft will travel to a near-Earth asteroid, called Bennu (formerly 1999 RQ36), and bring at least a 2.1-ounce sample back to Earth for study. The mission will help scientists investigate how planets formed and how life began, as well as improve our understanding of asteroids that could impact Earth.
The video above is a time lapse sequence of the touch down, sampling, and subsequent take off.
These images were captured over approximately a five-minute period. The imaging sequence begins at about 82 feet (25 meters) above the surface, and runs through the back-away maneuver, with the last image in the sequence taken at approximately 43 feet (13 meters) in altitude — about 35 seconds after backing away. The sequence was created using 82 SamCam images, with 1.25 seconds between frames.
Above from top to bottom: Nicolas Lefaudeux’s tilt-shift shot of the Andromeda Galaxy, Alain Paillou’s ultra-contrasty photo of the Moon, Kristina Makeeva’s aurora shot, Evan McKay’s self-portrait under the Milky Way, and Olga Suchanova’s 3-month exposure of the Sun’s path through the sky using a beer can pinhole camera. You can read a little bit about how Suchanova got that shot on 35mmc:
If exposure times on the order of minutes seem long, try months. Olga Suchanova (London, UK) used a pinhole camera made from a beercan — and not just any beercan, but a Peter Saville design for the Tate Modern — to record the solargraph below.
She used Ilford paper, exposed for 3 or 4 months at an art residency in Almeria, Spain. The long exposure traces the sun’s path across the sky over multiple days — sunny days make brighter lines, and as spring turns to summer, the sun rises higher in the sky. The fantastic colours — another consequence of the long exposure — are created spontaneously on black and white paper, without the need for development or any other chemical processing.
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