Black holes are some of the most bizarre and fascinating objects in the cosmos. Astronomers want to study lots of them, but there’s one big problem – black holes are invisible! Since they don’t emit any light, it’s pretty tough to find them lurking in the inky void of space. Fortunately there are a few different ways we can “see” black holes indirectly by watching how they affect their surroundings.
If you’ve spent some time stargazing, you know what a calm, peaceful place our universe can be. But did you know that a monster is hiding right in the heart of our Milky Way galaxy? Astronomers noticed stars zipping superfast around something we can’t see at the center of the galaxy, about 10 million miles per hour! The stars must be circling a supermassive black hole. No other object would have strong enough gravity to keep them from flying off into space.
Two astrophysicists won half of the Nobel Prize in Physics last year for revealing this dark secret. The black hole is truly monstrous, weighing about four million times as much as our Sun! And it seems our home galaxy is no exception – our Hubble Space Telescope has revealed that the hubs of most galaxies contain supermassive black holes.
Technology has advanced enough that we’ve been able to spot one of these supermassive black holes in a nearby galaxy. In 2019, astronomers took the first-ever picture of a black hole in a galaxy called M87, which is about 55 million light-years away. They used an international network of radio telescopes called the Event Horizon Telescope.
In the image, we can see some light from hot gas surrounding a dark shape. While we still can’t see the black hole itself, we can see the “shadow” it casts on the bright backdrop.
Black holes can come in a smaller variety, too. When a massive star runs out of the fuel it uses to shine, it collapses in on itself. These lightweight or “stellar-mass” black holes are only about 5-20 times as massive as the Sun. They’re scattered throughout the galaxy in the same places where we find stars, since that’s how they began their lives. Some of them started out with a companion star, and so far that’s been our best clue to find them.
Some black holes steal material from their companion star. As the material falls onto the black hole, it gets superhot and lights up in X-rays. The first confirmed black hole astronomers discovered, called Cygnus X-1, was found this way.
If a star comes too close to a supermassive black hole, the effect is even more dramatic! Instead of just siphoning material from the star like a smaller black hole would do, a supermassive black hole will completely tear the star apart into a stream of gas. This is called a tidal disruption event.
But what if two companion stars both turn into black holes? They may eventually collide with each other to form a larger black hole, sending ripples through space-time – the fabric of the cosmos!
These ripples, called gravitational waves, travel across space at the speed of light. The waves that reach us are extremely weak because space-time is really stiff.
Three scientists received the 2017 Nobel Prize in Physics for using LIGO to observe gravitational waves that were sent out from colliding stellar-mass black holes. Though gravitational waves are hard to detect, they offer a way to find black holes without having to see any light.
We’re teaming up with the European Space Agency for a mission called LISA, which stands for Laser Interferometer Space Antenna. When it launches in the 2030s, it will detect gravitational waves from merging supermassive black holes – a likely sign of colliding galaxies!
So we have a few ways to find black holes by seeing stuff that’s close to them. But astronomers think there could be 100 million black holes roaming the galaxy solo. Fortunately, our Nancy Grace Roman Space Telescope will provide a way to “see” these isolated black holes, too.
Roman will find solitary black holes when they pass in front of more distant stars from our vantage point. The black hole’s gravity will warp the starlight in ways that reveal its presence. In some cases we can figure out a black hole’s mass and distance this way, and even estimate how fast it’s moving through the galaxy.
For more about black holes, check out these Tumblr posts!
⚫ Gobble Up These Black (Hole) Friday Deals!
⚫ Hubble’s 5 Weirdest Black Hole Discoveries
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
Horseshoe bend, Arizona.
Crédito: Felix Barra
https://www.facebook.com/felix.barra.5
Amanecer del 2 de Enero, cerca del Lago Ontario en Canada.
Hoy nuestro planeta pasó por su Perihelio, es decir, por el punto de su órbita más cercano al Sol. En ese momento, aunque sea imperceptible para los humanos, viajamos la endiablada velocidad de 110.700 kilómetros por hora (o, lo que es lo mismo, 30,75 kilómetros por segundo).
Crédito: Steven A. Sweet
Lunar 101-Moon Book
On October 20th, our OSIRIS-REx mission will make its first attempt to collect and retrieve a sample of asteroid Bennu, a near-Earth asteroid. On sample collection day, Bennu will be over 200 million miles away from Earth.
Asteroids are the building blocks of our solar system. A sample of this ancient material can tell us about the history of our planet and the origins of life. Science results published from the mission on October 8th confirm that Bennu contains carbon in a form often found in biology or in compounds associated with biology.
To collect a sample, OSIRIS-REx will attempt a method NASA has never used before – called Touch-And-Go (TAG). First, the spacecraft extends its robotic sampling arm, the Touch-And-Go Sample Acquisition Mechanism (TAGSAM) – from its folded storage position. The spacecraft’s two solar panels then move into a “Y-wing” configuration over the spacecraft’s body, which positions them safely up and away from the asteroid’s surface during touch down. This configuration also places the spacecraft’s center of gravity directly over the TAGSAM collector head, which is the only part of the spacecraft that will contact Bennu’s surface.
Finding a safe sample collection site on Bennu’s rocky landscape was a challenge. During the sampling event, the spacecraft, which is the size of a large van, will attempt to touch down in an area that is only the size of a few parking spaces, and just a few steps away from enormous boulders.
The spacecraft will only make contact with Bennu for a matter of seconds - just long enough to blow nitrogen gas onto the surface to roil up dust and small pebbles, which will then be captured for a return to Earth.
We need to conduct a few tests before we can confirm we collected a large enough sample (about 2 oz). First, OSIRIS-REx will take images of the collector head to see if it contains rocks and dust. Second, the spacecraft will spin with the TAGSAM extended to determine the mass of collected material. If these measures show a successful collection, we will stow the sample for return to Earth. If sufficient sample has not been collected, the spacecraft has onboard nitrogen charges for two more attempts. The next TAG attempt would be made no earlier than January 2021.
Despite the many challenges, the OSIRIS-REx team is ready. They’ve practiced and prepared for this moment.
Join in with #ToBennuAndBack and tune in on October 20th.
Learn more about the OSIRIS-REx countdown to TAG HERE.
Learn more about the OSIRIS-REx mission HERE, or follow the mission on Facebook, Twitter and Instagram.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Our Nancy Grace Roman Space Telescope team recently flight-certified all 24 of the detectors the mission needs. When Roman launches in the mid-2020s, the detectors will convert starlight into electrical signals, which will then be decoded into 300-megapixel images of huge patches of the sky. These images will help astronomers explore all kinds of things, from rogue planets and black holes to dark matter and dark energy.
Eighteen of the detectors will be used in Roman’s camera, while another six will be reserved as backups. Each detector has 16 million tiny pixels, so Roman’s images will be super sharp, like Hubble’s.
The image above shows one of Roman’s detectors compared to an entire cell phone camera, which looks tiny by comparison. The best modern cell phone cameras can provide around 12-megapixel images. Since Roman will have 18 detectors that have 16 million pixels each, the mission will capture 300-megapixel panoramas of space.
The combination of such crisp resolution and Roman’s huge view has never been possible on a space-based telescope before and will make the Nancy Grace Roman Space Telescope a powerful tool in the future.
Learn more about the Roman Space Telescope!
Make sure to follow us on Tumblr for your regular dose of space!
Debajo del meteoro de las Perseidas, los árboles se alzan en silueta contra las luces dispersas a lo largo del horizonte y la débil Vía Láctea, a su vez cortada por oscuras nubes de polvo interestelar.
Créditos: Jared Tennant
"Night Sky"
La Vía Láctea sobre Dead Vlei en el desierto de Namib en Namibia.
Panorama de 3 fotos individuales: Sony A75 l Sigma mm F / 1 .8 || s l IS0 5000
Crédito: Stefan Liebermann
https://instagram.com/stefanliebermannphoto
https://www.stefanliebermann.de/
~Antares
Halloween is just around the corner. Need some chilling décor? We’ve got you – and your walls – covered with three new Galaxy of Horrors posters that showcase some of the most terrifying topics in the universe.
In the depths of the universe, the cores of two collapsed stars violently merge to release a burst of the deadliest and most powerful form of light, known as gamma rays. These beams of doom are unleashed upon their unfortunate surroundings, shining a billion trillion times brighter than the Sun for up to 30 terrifying seconds. No spaceship will shield you from their blinding destruction!
The chillingly haunted galaxy called MACS 2129-1 mysteriously stopped making stars only a few billion years after the Big Bang. It became a cosmic cemetery, illuminated by the red glow of decaying stars. Dare to enter and you might encounter the frightening corpses of exoplanets or the final death throes of once-mighty stars.
Something strange and mysterious creeps throughout the cosmos. Scientists call it dark matter. It is scattered in an intricate web that forms the skeleton of our universe. Dark matter is invisible, only revealing its presence by pushing and pulling on objects we can see. NASA’s Roman Space Telescope will investigate its secrets. What will it find?
Download the full set in English and Spanish here.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Región activa solar AR2786 (Izquierda) y AR2785 (Derecha) en comparativa con nuestro planeta.
Crédito: Paul's Astrophotography
Tránsito de la Estación Espacial Tiangong
Se utilizo un refractor de 8 ′′ a lo largo del Mar Mediterráneo, para este tránsito solar de 1/2 segundo de la nueva Estación Espacial Tiangong de China, que incluye los 3 módulos con sus paneles solares y sin duda el brazo robótico. Pueden acceder al video de este tránsito a través de su canal de YouTube o el siguiente link:
https://www.youtube.com/watch?v=Bp3jCKvX_tY
Credito: Thierry Legault
https://www.facebook.com/thierry.legault.5
~Antares
Torcal de Antequera es un paraje natural situado en los términos municipales de Antequera y Villanueva de la Concepción de la provincia de Málaga, en Andalucía (España).
Crédito: Juanma Espinosa
https://instagram.com/juanmaespinosa
~Antares
Glaretum fundado en el 2015 con el objetivo de divulgar la ciencia a través de la Astronomía hasta convertirnos en una fuente de conocimiento científico veraz siendo garantía de información seria y actualizada.
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