Hello Space Fans and welcome to another edition of Space Fan News.
Ever since I started doing Space Fan News, on a regular basis I've been reporting on
increases in estimates of the number of planets that are in the universe.
If you've followed this show for any length of time, you've heard me talk about percentages
of stars that have planets and most recently, I said every star in our galaxy has on average
1.6 planets in orbit around it.
Well, guess what?
Astronomers from the Harvard Center for Astrophysics are saying, you know what?
Forget percentages and averages, they're saying flat out that every star has a planet.
Every one.
The reason there's been so much hemming and hawing over past estimates (there's this many
planets, no there's even more than we thought, oh wait, there's even more than that) is that
astronomers always assumed you needed a certain amount of time to pass (the universe needed
to be a certain age) so that stars could live long enough to have the raw materials to create
planets from.
Stars with lots of these elements are called high metallicity stars (everything higher
than helium is called a metal in astronomy).
This idea always constrained how many planets there could be in the universe because stars
hadn't created the stuff necessary to make them yet.
Well these guys using Kepler data of 150 stars have found that only giant planets need stars
with high metallicity to form.
Rocky planets don't have that preference, they found lots of smaller, rocky planets
around stars with a wide range of metallicities, with some as little as 25% of the Sun's metal
content.
This means that smaller, rocky planets could have formed at any time in the history of
the universe - we don't need many, many generations of stars before you start to get planets.
So this has pretty big implications.
Most notably that if every star has a planet and the universe could have started producing
them pretty much anytime (after all, low metal stars have been around since the beginning
of the universe), and if life has a preference for rocky worlds (we don't know that, but
based on our experience it might), then we could expand our search for life elsewhere
to lots more places.
And life could, in fact, be everywhere.
But in a way, this news is alarming.
If the stage and conditions for life are so common as we're starting to find, then Fermi's
Paradox starts to loom large (in my head at least).
Where is everybody?
If planets can form at any time and every star has one, then the opportunity for life
to emerge is actually quite large.
We haven't detected any galaxy dominating civilizations yet, so if we find life is common,
one of two things are happening: either life stays at some simple stage in development
and never gets very far into space, or something is filtering out the ones that do make it
that far.
And whatever that filter is, whatever it is that prevents civilizations for reaching the
stars, is still somewhere ahead of us and we have yet to face it.
Something to think about.
Next, NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, has successfully deployed
its 10-meter long mast that will focus X-rays onto its detectors.
X-rays are hard to focus, you can't just bounce them off a mirror like you can other, longer
wavelengths, as anybody who's every had an x-ray knows, they pass just pass through everything.
So the best we can do is to graze the incoming x-ray photons just a little bit off of a set
of nested mirrors and NuStar has about 133 of them, 133 layers of mirrors all nest within
each other.
So now that the mast is deployed, they can begin running the telescope through its tests,
start pointing it at things and fine tuning the alignment of the mast.
This process reminded me a little of what the Webb Space Telescope is going to have
to do.
Its reminiscent of the heat shield deployment except that where the NuStar mast was deployed
in 26 minutes, the Webb Space Telescope heat shield will take weeks to fully deploy.
Because it's so important (it won't work without it), they are going to take their sweet time
getting all five layers fully stretched out.
Finally, astronomers working with NASA's Chandra X-ray Observatory have found strong evidence
that a massive black hole is being ejected from its host galaxy at a speed of several
million miles per hour.
New observations suggest that the black hole collided and merged with another black hole
and received a powerful recoil kick from the gravity waves that collision created.
Now I haven't heard much about gravity waves in a long time, but if this scenario is true,
then they much be pretty powerful things.
I mean think about it, it's hard to imagine moving a black hole millions of times the
size of the sun at all, much less kick it out of a galaxy, so this interaction must
have created some pretty strong gravity waves.
They're saying this kind of event is likely pretty rare, but it would mean that there
are black holes out there lurking in the spaces between the galaxies, not just in the galaxies
themselves.
They found this by studying a system known as CID-42, located in the middle of a galaxy
about four billion light years away.
They had previously spotted two distinct, compact sources of optical light in CID-42,
using the Hubble Space Telescope.
They also used other spectrum data from the ground-based Magellan and Very Large Telescopes
in Chile that suggested the two sources in CID-42 are moving apart at a speed of at least
3 million miles per hour.
So when they pointed Chandra's High Resolution Camera straight at CID-42, it showed X-rays
coming from only one of the sources.
What they think happened is that when the two galaxies collided, the two supermassive
black holes also collided creating huge gravity waves that threw it out of the galaxy after
they merged.
These gravity waves were powerful enough to send the black hole flying out of the galaxy.
Now that is just like downtown.
There are two other possible explanations for what is happening in CID-42.
One would involve an encounter between three supermassive black holes, resulting in the
lightest one being ejected.
Another idea is that CID-42 contains two supermassive black holes spiraling toward one another,
rather than one moving quickly away.
Well, that's it for this week Space Fans, thank you for watching, and as always, Keep
Looking Up!