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Interstellar meteor confirmed to have collided with Earth in 2014, researchers say – CTV News

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One meteor travelled quite a long way from home to visit Earth.

Researchers discovered the first known interstellar meteor to ever hit Earth, according to a recently released United States Space Command document. An interstellar meteor is a space rock that originates from outside our solar system — a rare occurrence.

This one is known as CNEOS 2014-01-08, and it crash-landed along the northeast coast of Papua New Guinea on January 8, 2014.

The finding came as a surprise to Amir Siraj, who identified the object as an interstellar meteor in a 2019 study he coauthored while an undergraduate at Harvard University.

Siraj was investigating ʻOumuamua, the first known interstellar object in our solar system that was found in 2017, with Abraham Loeb, professor of science at Harvard University.

Siraj decided to go through NASA’s Center for Near Earth Object Studies database to find other interstellar objects and found what he believed to be an interstellar meteor within days.

A NEED FOR SPEED

The meteor’s high velocity is what initially caught Siraj’s eye.

The meteor was moving at a high speed of about 28 miles per second (45 kilometres per second) relative to Earth, which is moving at around 18.6 miles per second (30 kilometres per second) around the sun. Because researchers measured how fast the meteor was moving while on a moving planet, the 45 kilometres per second was not actually how fast it was going.

The heliocentric speed is defined as the meteor’s speed relative to the sun, which is a more accurate way to determine an object’s orbit. It’s calculated based on the angle at which a meteor hits the Earth. The planet moves in one direction around the sun, so the meteor could have hit Earth head-on, meaning opposite the direction the planet is moving, or from behind, in the same direction the Earth is moving.

Since the meteor hit the Earth from behind, Siraj’s calculations said the meteor was actually traveling at about 37.3 miles per second (60 kilometres per second) relative to the sun.

He then mapped out the trajectory of the meteor and found it was in an unbound orbit, unlike the closed orbit of other meteors. This means that rather than circling around the sun like other meteors, it came from outside the solar system.

“Presumably, it was produced by another star, got kicked out of that star’s planetary system and just so happened to make its way to our solar system and collide with Earth,” Siraj said.

DIFFICULTY GETTING PUBLISHED

Loeb and Siraj have been unable to get their findings published in a journal because their data came from NASA’s CNEOS database, which doesn’t divulge information such as how accurate the readings are.

After years of trying to obtain the additional information needed, they received official confirmation that it was, in fact, an interstellar meteor, from John Shaw, deputy commander of the U.S. Space Command. The command is a part of the U.S. Department of Defense and is responsible for military operations in outer space.

“Dr. Joel Mozer, the Chief Scientist of Space Operations Command, the United States Space Force service component of U.S. Space Command, reviewed analysis of additional data available to the Department of Defense related to this finding. Dr. Mozer confirmed that the velocity estimate reported to NASA is sufficiently accurate to indicate an interstellar trajectory,” wrote Shaw in the letter.

Siraj had moved onto other research and almost forgotten about his discovery, so the document came as a shock.

“I thought that we would never learn the true nature of this meteor, that it was just blocked somewhere in the government after our many tries, and so actually seeing that letter from the Department of Defense with my eyes was a really incredible moment,” Siraj said.

A SECOND CHANCE

Since receiving the confirmation, Siraj said his team is working to resubmit their findings for publication in a scientific journal.

Siraj would also like to put a team together to try and retrieve part of the meteor that landed in the Pacific Ocean but admitted it would be an unlikely possibility due to the sheer size of the project.

If researchers were able to get their hands on the “holy grail of interstellar objects,” Siraj said it would be scientifically groundbreaking in helping scientists discover more about the world beyond our solar system.

NASA and US Space Command did not initially respond for comment.

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Photos: Total lunar eclipse bathes Moon in red – Al Jazeera English

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Skywatchers have gathered in different parts of the globe to enjoy a total lunar eclipse that graced the skies for longer than usual.

For about an hour and a half on Sunday night into early Monday morning, the Moon was bathed in the reflected red and orange hues of the Earth’s sunsets and sunrises.

It was one of the longest totalities of the decade and the first so-called “Blood Moon” in a year.

Observers in the eastern half of North America and all of Central and South America had prime seats for the whole show, weather permitting.

Partial stages of the eclipse were visible across Africa, Europe and the Middle East.

A total eclipse occurs when the Earth passes directly between the moon and the sun and casts a shadow on our constant, cosmic companion.

The moon was expected to be 362,000km (225,000 miles) away at the peak of the eclipse.

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Q and A: She discovered the black hole at the center of our galaxy. This week, she finally saw it – Phys.org

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Credit: EHT Collaboration, CC BY-SA

This week, the world got its first-ever look at Sagittarius A*, the supermassive black hole in the center of our galaxy. The image of a hazy golden ring of superheated gas and bending light was captured by the Event Horizon Telescope, a network of eight radio observatories scattered across the globe.

Feryal Özel, a University of Arizona astronomer and founding member of the EHT consortium, said that seeing the black hole’s image was like finally meeting in real life a person you’ve only interacted with online.

For Andrea Ghez, an astrophysicist at UCLA, the encounter was perhaps more like a biographer meeting her subject after decades of pursuit.

In 2020, Ghez was awarded the Nobel Prize in physics for her role in the discovery of a supermassive object at the core of the Milky Way. That object is now known to be Sagittarius A*, or Sgr A* for short.

Ghez studies the center of our galaxy and the orbits of thousands of stars encircling the dense object at its very heart. Though she wasn’t involved with the EHT project, she said its “impressive” achievements—including its 2019 unveiling of the black hole anchoring a distant galaxy known as Messier 87—offer intriguing new possibilities for the study of the cosmos.

The Los Angeles Times spoke to her about black holes, cosmic surprises and what Einstein has to do with the GPS app on your phone. The interview has been edited for length and clarity.

How does it feel to finally lay eyes on the thing you’ve spent your career studying?

It’s super exciting. We live in a really interesting moment where technology is advancing so rapidly in so many arenas and giving us new insights into these incredibly exotic objects.

Does it look different than you anticipated?

No, actually. It’s remarkably similar. You should see this ring at roughly two and a half times the Schwarzschild radius (the radius of the event horizon, the boundary around a black hole beyond which no light or matter can escape). That’s the prediction of where gravity should bend, and that’s exactly where you see it. That’s impressive.

How much have technological capabilities changed for researchers since you started studying black holes?

Huge, huge advances. I often say we’re surfing on a wave of technological development. Everything that we do really can be described as technology-enabled discovery.

One of the things that I love about working in these areas where the technology is evolving really quickly is that it affords you the opportunity to see the universe in a way you haven’t been able to see before. And so often that reveals unexpected discoveries.

We’re really lucky that we’re living at this moment where technology is evolving so quickly that you can really rewrite the textbooks. The Event Horizon Telescope is a similar story.

What unanswered questions about the universe excite you most?

I have a couple favorites right now. The one that I’m super excited about is our ability to test how gravity works near the using star orbits, and also as a probe of dark matter at the center of the galaxy. Both of those things should imprint on the orbits.

A simple way that I like to think about it is: The first time around, these orbits tell you the shape. And then after that you get to probe more detailed questions because you kind of know where in space the star is.

For example, S0-2 (which is my favorite star in the galaxy, and probably in the universe) goes around every 16 years. Now we are on the second passage, and that’s giving us the opportunity to test Einstein’s theories in ways that are different than what the Event Horizon Telescope is probing, as well to constrain the amount of dark matter that you might expect at the center of the galaxy. There are things that we don’t understand about the early results, and to me that’s always the most exciting part of a measurement—when things don’t make sense.

What’s your approach in those moments?

You have to have complete integrity with your process. Things may not make sense because you’re making a mistake, which is the uninteresting result, or they may not make sense because there’s something new to be discovered. That moment when you’re not sure is super interesting and exciting.

We’ve just discovered these objects at the center of the galaxy that seem to stretch out as they get close to the black hole, then become more compact. They’re called tidal interactions. If you think of the movie “Interstellar” with that big giant tidal wave, this would be like a big tidal wave that just lifts off the planet. If we’re seeing stars having those kinds of interactions, it means that the star has to be, I don’t know, a hundred times larger than anything we predicted to exist in this region. So that makes you scratch your head.

Does the new image of Sgr A* reinforce your finding that, for now, Einstein’s theory of general relativity seems to do the best job of explaining how gravity operates throughout the universe?

Yes. Absolutely. Black holes kind of represent the breakdown of our understanding of how gravity works. We don’t know how to make gravity and quantum mechanics work together. And you need those two things to work together to explain what a black hole is, because a black hole is strong gravity plus an infinitesimally small object.

Wait, what? I thought black holes were huge

No. The image is of the phenomena that happens around the black hole. The black hole has no finite size, but there is this abstract size of the event horizon, which is the last point that light can escape. And then the gravitational interaction with local light gets concentrated in this ring that’s two-and-a-half times bigger that the event horizon.

Anyway, we know that represent the breakdown of our knowledge. That’s why everyone keeps testing Einstein’s ideas about gravity there, because at some point you expect to see what you might call the expanded version of gravity, in the same way that Einstein was the expanded version of Newton’s version.

Is it fair to say that Newton’s laws do a decent job of explaining how gravity works here on our little planet, but we need Einstein once we head out into the universe?

Yes, except for what we take for granted today: our cellphones. The fact that we can find ourselves so well on Google or Waze or your favorite traffic app is because GPS systems position your phone with respect to satellites going around the Earth. Those systems have to use Einstein’s version of gravity. So, yes. We could use Newton until we cared about things like this.


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Seeing Milky Way’s new black hole is ‘only the beginning’: US researcher


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Citation:
Q and A: She discovered the black hole at the center of our galaxy. This week, she finally saw it (2022, May 16)
retrieved 16 May 2022
from https://phys.org/news/2022-05-black-hole-center-galaxy-week.html

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You’ve Seen the New Image of the Milky Way’s Black Hole – Now Hear It! – SciTechDaily

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This is a sonification — translation into sound — of the latest image from the Event Horizon Telescope (EHT) of the supermassive black hole at the center of the Milky Way called Sagittarius A* (Sgr A*). Using a radar-like scan, the sonification begins at the 12 o’clock position and sweeps clockwise. Changes in the volume represent the differences in brightness the EHT observed around the event horizon of Sgr A*. The material that is closer to the <span class="glossaryLink" aria-describedby="tt" data-cmtooltip="

black hole
A black hole is a place in space where the pull of gravity is so strong not even light can escape it. Astronomers classify black holes into three categories by size: miniature, stellar, and supermassive black holes. Miniature black holes could have a mass smaller than our Sun and supermassive black holes could have a mass equivalent to billions of our Sun.

” data-gt-translate-attributes=”["attribute":"data-cmtooltip", "format":"html"]”>black hole and hence moving faster corresponds to higher frequencies of sound. This sonification was processed in a special way to allow a listener to hear the data in 3D stereo sound, in which the sounds seem to start directly ahead and then move clockwise to one ear and then the other as the sweep is made.

[embedded content]

About the Sound:

  • This is a radar-like scan, starting from 12 o’clock and moving clockwise.
  • The brightness controls the volume and the radial position controls the frequencies that are present.
  • The emission from material closer to the black hole (which orbits faster) is mapped to higher frequencies.
  • The sound is rendered in binaural audio. When listened to with headphones, the sound will appear to start directly in front of you and then move clockwise all the way around your head.
  • Listen for the three bright regions at about 1, 5, and 9 o’clock, as well as the very low tones indicating fainter light from outside the main ring.

Sonification Credit: <span class="glossaryLink" aria-describedby="tt" data-cmtooltip="

NASA
Established in 1958, the National Aeronautics and Space Administration (NASA) is an independent agency of the United States Federal Government that succeeded the National Advisory Committee for Aeronautics (NACA). It is responsible for the civilian space program, as well as aeronautics and aerospace research. It's vision is &quot;To discover and expand knowledge for the benefit of humanity.&quot;

” data-gt-translate-attributes=”["attribute":"data-cmtooltip", "format":"html"]”>NASA/CXC/SAO/K.Arcand, SYSTEM Sounds (M. Russo, A. Santaguida);

Image Credit: Radio: EHT Collaboration; X-ray (NASA/CXC/SAO); Infrared (NASA/HST/STScI)

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