This Week in Astronomy: SPHEREx, Dark Dwarfs and an Interestellar Object

<v Speaker 1>Welcome to Bedtime Astronomy. Explore the wonders of the cosmos
<v Speaker 1>with our soothing Bedtime Astronomy podcast. Each episode offers a
<v Speaker 1>gentle journey through the stars, planets, and beyond, perfect for
<v Speaker 1>unwinding after a long day. Let's travel through the mysteries
<v Speaker 1>of the universe as you drift off into a peaceful
<v Speaker 1>slumber under the night sky. This week in Astronomy, SPHEREx,
<v Speaker 1>Dark dwarfs and an interstellar object. SPHEREx, NASA's new telescope
<v Speaker 1>maps the entire sky in infrared. NASA recently launched a
<v Speaker 1>new space telescope called SPHEREx, which started its mission in March.
<v Speaker 1>This telescope is now orbiting the Earth and has begun
<v Speaker 1>scanning the entire sky to create a massive, detailed map
<v Speaker 1>of the universe. What makes this mission special is that
<v Speaker 1>Spherrex sends the data it collects to a public archive
<v Speaker 1>every week. That means anyone, scientists, students, or curious people
<v Speaker 1>can use this information to explore space and study how
<v Speaker 1>the universe works. SPHEREx stands for Spectrophotometer for the History
<v Speaker 1>of the Universe, Epic of Reonization, and ICE's Explorer. It
<v Speaker 1>looks at the sky using infrared light, a type of
<v Speaker 1>light that's invisible to our eyes but very useful in
<v Speaker 1>space science. Unlike some past missions, like NASA's earlier Wise telescope,
<v Speaker 1>which used four infrared wavelengths, SPHEREx observes the sky in
<v Speaker 1>one hundred and two different infrared wavelengths. This gives scientists
<v Speaker 1>a much more detailed view. By using all of these
<v Speaker 1>wavelengths together, researchers can detect the presence of specific molecules
<v Speaker 1>in space through a technique called spectroscopy. This allows them
<v Speaker 1>to study where frozen water and organic molecules, ingredients important
<v Speaker 1>for life, are located in the Milky Way Galaxy, the
<v Speaker 1>key pieces of the puzzle for understanding how stars, planets,
<v Speaker 1>and possibly life itself begin to form. But that's not
<v Speaker 1>all SPHEREx can do. Scientists will also use the data
<v Speaker 1>to investigate what caused the universe to expand after the
<v Speaker 1>Big Bang and how much light all the galaxies have
<v Speaker 1>emitted over time. Because the data has made public, scientists
<v Speaker 1>around the world can study many different things that go
<v Speaker 1>beyond what the original SPHEREx team could cover by themselves.
<v Speaker 1>NASA is committed to open science, which means they want
<v Speaker 1>everyone to have access to the data, so SPHEREx sends
<v Speaker 1>its data to a public archive within sixty days of
<v Speaker 1>collecting it. In that short time, the SPHEREx team processes
<v Speaker 1>the data. They clean it up, correct technical issues from
<v Speaker 1>the detectors, and make sure everything is properly aligned with
<v Speaker 1>the stars and galaxies in the sky. Over its two
<v Speaker 1>year main mission, SPHEREx will skin the entire sky twice
<v Speaker 1>a year, making four full sky maps in total. After
<v Speaker 1>one year, they plan to release a full map showing
<v Speaker 1>the sky in all one hundred and two infrared wavelengths.
<v Speaker 1>The data from SPHEREx is especially useful when combined with
<v Speaker 1>other space missions. For example, it can help NASA's James
<v Speaker 1>Webb Space Telescope choose better targets to study. It can
<v Speaker 1>also improve the accuracy of planet data from the Test
<v Speaker 1>mission and support research into dark matter and dark energy
<v Speaker 1>when used with the European Space Agency's EUCLID mission or
<v Speaker 1>NASA's future Roman Space Telescope. All this data is stored
<v Speaker 1>in NASA's IRSA Archive Infrared Science Archive, which already holds
<v Speaker 1>information from past space missions. Together, this creates a rich
<v Speaker 1>collection of space data that researchers can use to explore
<v Speaker 1>all kinds of cosmic mysteries. SPHEREx is now part of
<v Speaker 1>NASA's long tradition of space surveys. As one scientist said,
<v Speaker 1>people are going to find all sorts of creative and
<v Speaker 1>surprising ways to use the data, many of which we
<v Speaker 1>can't even imagine yet. Dark dwarfs may reveal the true
<v Speaker 1>nature of dark matter. Some scientists think there might be
<v Speaker 1>a new kind of object hidden in the center of
<v Speaker 1>our galaxy. These mysterious things are called dark dwarfs, and
<v Speaker 1>they could help explain one of the biggest mysteries in
<v Speaker 1>the universe, what dark matter really is. A group of
<v Speaker 1>researchers from the UK and Hawaii wrote a paper about
<v Speaker 1>these dark dwarfs. They believe we could find them using
<v Speaker 1>powerful telescopes we already have, like the James Webb Space Telescope.
<v Speaker 1>They gave them the name dark dwarfs because of their
<v Speaker 1>strong connection with dark matter, not because they are actually
<v Speaker 1>dark in appearance. Dark matter is a strange kind of
<v Speaker 1>matter that makes up about twenty five percent of the universe.
<v Speaker 1>We can't see it because it doesn't give off flight,
<v Speaker 1>but we know it's there because of the way it
<v Speaker 1>affects gravity. Even those scientists have studied it for decades,
<v Speaker 1>nobody knows exactly what it is. That's why research like
<v Speaker 1>this is exciting. It might give us clues. There's a
<v Speaker 1>popular idea that dark matter is made of very heavy
<v Speaker 1>particles that don't interact with normal matter. These particles are
<v Speaker 1>called whimps, weakly interacting massive particles. They're invisible and silent,
<v Speaker 1>but they do have gravity. If dark matter is made
<v Speaker 1>of whimps, then it might be possible for some stars
<v Speaker 1>to catch and hold them. If enough of this dark
<v Speaker 1>matter builds up inside a star, the particles might destroy
<v Speaker 1>each other annihilate, which releases energy and makes the star shine.
<v Speaker 1>Regular stars like our sun shine because of nuclear fusion
<v Speaker 1>in their course, but that only happens when a star
<v Speaker 1>is big enough. If a star is too small, like
<v Speaker 1>only eight percent the size of our sun, it can't
<v Speaker 1>start fusion. These small stars are called brown dwarfs, and
<v Speaker 1>they're usually very dim. But if a brown dwarf is
<v Speaker 1>in a place with lots of dark matter, like the
<v Speaker 1>center of the galaxy, it could collect enough of it
<v Speaker 1>to start glowing, not because of fusion, but because of
<v Speaker 1>the energy from the dark matter inside it. When that happens,
<v Speaker 1>it's no longer just a brown dwarf. It becomes a
<v Speaker 1>dark dwarf. This only works if dark matter is made
<v Speaker 1>of the heavy self interacting kind like whimps. Other ideas
<v Speaker 1>for dark matter, like axioms or ultra light particles wouldn't
<v Speaker 1>work because they're too light and can't create the same
<v Speaker 1>energy inside stars. The scientists also thought of a way
<v Speaker 1>to tell if something is a dark dwarf and not
<v Speaker 1>just a normal brown dwarf. They say to look for
<v Speaker 1>lithium seven, a special version of lithium. Regular stars burn
<v Speaker 1>through lithium seven quickly, so if we find a glowing
<v Speaker 1>object with lithium seven still in it, it could be
<v Speaker 1>a sign that it's a dark dwarf. Telescopes like James
<v Speaker 1>Webb might already be able to spot these dark dwarfs,
<v Speaker 1>especially if we look at groups of faint stars and
<v Speaker 1>study their patterns. If we find one or more dark dwarfs,
<v Speaker 1>that would be a strong clue that dark matter is
<v Speaker 1>made of whimps or something very similar. We still wouldn't
<v Speaker 1>be one hundred percent sure what dark matter is, but
<v Speaker 1>it would narrow it down a lot. Finding a dark
<v Speaker 1>dwarf wouldn't solve the whole mystery, but it would be
<v Speaker 1>a big step forward in understanding this invisible part of
<v Speaker 1>the universe. Late on July first, twenty twenty five, astronomers
<v Speaker 1>watching the skies with an asteroid warning system spotted something unusual.
<v Speaker 1>A big, bright object was moving quickly through the Solar System.
<v Speaker 1>It immediately caught the attention of scientists around the world
<v Speaker 1>because it looked like it might have come from outside
<v Speaker 1>our Solar system. The next day, the European Space Agency
<v Speaker 1>confirmed that this object, first called a eleven PL three
<v Speaker 1>and later renamed three ice slash Atlas, really did come
<v Speaker 1>from beyond the Solar System. It's only the third object
<v Speaker 1>ever found that isn't originally from our solar neighborhood. Three
<v Speaker 1>ice slash Atlas is very large, about twenty kilometers wide,
<v Speaker 1>and although it won't come close to Earth, it's still
<v Speaker 1>very interesting. Scientists believe it could help explain how planets
<v Speaker 1>form in other Solar systems and give more insight into
<v Speaker 1>the other two interstellar objects that were found before, Umyuamua
<v Speaker 1>and two ice slash Borisov. Each of those had very
<v Speaker 1>different features. Umyuamua didn't have a tail and moved in
<v Speaker 1>strange ways that weren't fully explained by gravity. Borisov looked
<v Speaker 1>more like a regular comet, but still had unusual parts
<v Speaker 1>in its makeup. Everyone expected the next object to look
<v Speaker 1>like one of those, but three ice slash atlasts doesn't
<v Speaker 1>look like either. That surprised and excited scientists. Object is
<v Speaker 1>much brighter than the others and is also much farther away,
<v Speaker 1>yet telescopes can still see it clearly. That's because it's
<v Speaker 1>so big. Since it's visible from far away, astronomers will
<v Speaker 1>have more time to study it than they did with
<v Speaker 1>Umuamua or boris Off. It's also moving very fast, which
<v Speaker 1>makes it even more unusual. At first, scientists weren't sure
<v Speaker 1>if it was really from outside the Solar System. Sometimes
<v Speaker 1>things seem interesting at first, but as more information comes
<v Speaker 1>in they turn out to be less exciting. But in
<v Speaker 1>this case, as more data was gathered, experts became more
<v Speaker 1>convinced that it really is interstellar. They could tell by
<v Speaker 1>looking at how the object moves. One of the main
<v Speaker 1>things that tells astronomers if something came from another star
<v Speaker 1>system is its orbit. Most objects in the Solar System
<v Speaker 1>travel in circles or stretched out circles called ellipsies. But
<v Speaker 1>if an object travels in a way that never loops
<v Speaker 1>back and instead shoots off into space, that's called a
<v Speaker 1>hyperbolic orbit. It means the object is not tied to
<v Speaker 1>the Sun's gravity and didn't come from this solar system.
<v Speaker 1>Scientists can figure this out by watching how fast the
<v Speaker 1>object is moving and comparing its position to the stars
<v Speaker 1>in the background. As they get more data, they update
<v Speaker 1>their understanding of its path through space. Interstellar objects like
<v Speaker 1>three ice slash Atlas are special because they are leftovers
<v Speaker 1>from how other solar systems formed. In our own solar system,
<v Speaker 1>small objects like asteroids and comets have taught us a
<v Speaker 1>lot about how planets were created. If we study an
<v Speaker 1>object from another system, we can learn how that system
<v Speaker 1>was different or similar to ours. Scientists are still trying
<v Speaker 1>to figure out what kind of object three ice slash
<v Speaker 1>Atlas is. It might be a comet like Borisov, or
<v Speaker 1>it might behaved strangely like Umuamua. If it turns out
<v Speaker 1>to be a comet, they will want to know if
<v Speaker 1>it contains ice. Ice tells scientists a lot about where
<v Speaker 1>the object came from. If the object still has ice
<v Speaker 1>it probably didn't spend much time near a star because
<v Speaker 1>the heat would have melted it. That would mean the
<v Speaker 1>object formed far from its star and was possibly pushed
<v Speaker 1>out by a giant planet like Jupiter or Neptune. In
<v Speaker 1>the end, this object might help scientists understand more about
<v Speaker 1>other parts of the galaxy. It's still early, but many
<v Speaker 1>telescopes are already focusing on it. In the coming days
<v Speaker 1>and weeks, scientists hope to gather much more information and
<v Speaker 1>possibly unlock new secrets about how planets form in distant
<v Speaker 1>solar systems. To do, as the name m