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Scientists can image all kinds of things in the universe, from galaxies and stars to the
radiation coming out of black holes.
But it’s really difficult to take a picture of a newborn planet.
They tend to be hard to find, out-shined by the light from their star, and obscured by
the dust clouds they form from.
But we’ve just done it.
No big deal.
On Monday, astronomers published the first confirmed image of a baby planet, and it already
has a lot to teach us.
The planet is called PDS 70b.
Which, like, I wouldn’t name my newborn that, but to each their own.
It’s probably less than 5.4 million years old — more than 1000 times younger than
the Earth — and it orbits a star around 370 light-years away called PDS 70.
We’ve known about the star for a few years now and have even taken images of it that
suggest a planet might be forming there.
But these new pictures are way clearer.
The image was taken using the SPHERE instrument on the European Southern Observatory’s Very
Large Telescope, which was built to take pictures of exoplanets in visible and near-infrared
light.
And this thing is really good at its job.
One of SPHERE’s biggest features is that it’s great at filtering out light from stars.
Unsurprisingly, stars are super bright, and they tend to outshine most things near them
— including baby planets.
SPHERE gets around this by taking multiple pictures of a star system over several hours,
which gives things like planets time to move around a bit.
Then, using a series of algorithms, the telescope’s computers filter out anything in the image
series that hasn’t moved — stuff like the star.
And that’s how it ended up with an image like this, where you can see that new planet
super clearly.
But SPHERE’s photo-taking skills aren’t just for pretty pictures.
The instrument captures star systems in multiple wavelengths of light — like near-infrared,
which can tell us how much heat an object is emitting.
So its observations can also tell us a bit about what this new planet is like.
From what we can tell so far, 70b is a gas giant about 3 billion kilometers from its
star — around the same distance as Uranus is from the Sun.
It’s several times the mass of Jupiter, and it’s hot, with a surface temperature
somewhere around 1000°C.
Observations do suggest it has a cloudy atmosphere, although we aren’t totally positive what
it’s made of.
So, maybe it only feels like 999°C.
Imaging and studying brand-new planets is important for astronomers because, right now,
there’s still a lot we don’t know about how they form.
So the earlier we can sneak in there and start collecting data, the better off we are.
The next step is to take a closer look at 70b with another telescope — like ALMA in
Chile — that will be able to capture things like its composition and temperature in even
more detail.
But considering SPHERE just took one of our best baby photos ever, I’d say scientists
are off to a pretty good start.
Much closer to home, another team of astronomers has been busy tracking down the origin of
our solar system’s asteroids.
Our neighborhood is filled with millions of them, and it’s easy to think of them as
random space rocks from… wherever.
But like everything else, those rocks have origins.
And according to a new paper, published Monday in Nature Astronomy, most of them have the
same origins.
The authors estimate that 85% of the asteroids in the part of the asteroid belt closest to
Mars came from just five parent bodies.
Which means the early solar system might’ve been a lot less populated than we thought.
Scientists can sort asteroids into all kinds of groups based on things like size and composition.
But when it comes to grouping them based on origins, there are two main categories: family
and non-family.
Family asteroids are those that came from the breakup of known objects, while non-family
asteroids have mysterious origins.
They were probably part of larger bodies, too, but we haven’t been able to figure
out what.
In their new paper, these authors argue that the answer is pretty simple: Most of those
orphan asteroids actually belong to some of the biggest families out there.
Specifically, ones called Flora, Vesta, Nysa, Polana, and Eulalia.
The remaining 15% probably come from so-called ghost families: Groups that have drifted apart
so much it’s difficult to tell where they started.
The team got their results by plotting data from more than 70,000 inner main belt asteroids
— those that are just past Mars, or around 310 to 370 million kilometers from the Sun
— and then comparing features of their orbits.
They looked at things like how circular and tilted their orbits are, as well as how the
asteroids are distributed by size.
The asteroids that started off as one body should have many of those features in common,
so if any non-family asteroids matched those patterns, maybe they belong in known families,
too.
And a lot of them did!
More than 40% of them, according to their results, which brings the total amount of
family asteroids in that area to 85%.
This suggests that we shouldn’t be thinking about these objects as lost asteroids, but
as part of large, established groups — something that will make studying them a lot easier.
So far, scientists have only looked at the inner main belt asteroids, since we have the
most observations about them.
But the authors believe their findings should apply to the rest of the main belt, too.
A helpful next step would be to confirm these results using other measurements — things
like size, reflectivity, and composition.
But this seems promising so far!
Knowing where asteroids came from is helpful not only for understanding the early solar
system, but for protecting the Earth, too.
After all, there is a chance — a small one, but still a chance — that one of those larger
asteroids could end up hurtling toward the Earth someday.
And if it does, knowing what it’s made of could help us deflect it or break it up.
I wouldn’t lose sleep over it or anything, but it’s always good to be prepared.
Thanks for watching this episode of SciShow Space News!
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