Welcome back to part 2 of our investigation into the new monster telescopes under construction.
In the first part, we talked about the ground-based telescopes being built at various places around
the world - largest of which will more than triple the size of the biggest telescopes
we have right now.
With telescopes this size, astronomers will have the capability to peer into the Universe,
more more resolution than even our most powerful space-based telescopes.
Of course, there are a group of space-based telescopes in the works too.
Telescopes that absolutely dwarf the most sensitive telescopes we have in space already.
Ground telescopes are getting bigger.
Space telescopes are getting bigger too.
Allow me to get your imagination going with the space-based telescopes that’ll bring
us into the next golden age of astronomy.
Once again, a huge thanks to Universe Today’s Evan Gough, who created the original series
on our website.
First, we’ve got to start with a telescope I’m sure you’re familiar with: the James
Webb Space Telescope, currently under construction and planned for launch in October, 2018.
James Webb has had a long and difficult journey to get to its current state of development,
surviving cancellations, and going way over budget.
But from where we are now, everything’s coming together for its flight next year,
when it blasts into space atop an Ariane 5 rocket.
Consider the Hubble Space Telescope, with its 2.4 meter primary mirror, orbiting in
a Low Earth Orbit.
James Webb, instead, will head out to the Earth-Sun L2 Lagrange point, a region of relative
stability about 1.5 million kilometers from Earth.
Its primary mirror will be 6.5 meters across, made up of 18 separate segments.
James Webb will have 7 times more collecting area than Hubble, with the capability of seeing
things astronomers have only glimpsed up to now.
It’ll be able to see right out to the edge of the observable Universe, when the first
stars were forming.
It’ll be able to see the first galaxies forming in the early Universe, the birth of
new stars and planetary systems.
And most interestingly, planets and the origins of life.
James Webb will be able to directly image the atmospheres of extrasolar planets, searching
for evidence of life.
You might have heard that James Webb is the successor to Hubble, but that’s not exactly
true.
James Webb is an infrared telescope, which is a very useful wavelength, especially for
seeing cool and dust-obscured objects.
But Hubble can go from infrared through visible and into the ultraviolet.
But we’ll be talking about the true successor to Hubble later on in this episode.
James Webb will be a risky mission because it’s going out to the L2 point.
Unlike Hubble, it won’t be repairable or upgradeable.
Everything needs to go exactly right with the launch, insertion orbit, and the final
deployment of its folding primary mirror and sunshade.
The entire astronomical community is going to be on pins and needles, waiting for everything
to be complete and first light.
An unlike Hubble, James Webb has a set timeframe.
It only has enough fuel to maintain its position at the L2 point for about 10 years.
After that, it’ll drift away.
Next up, the Wide Field Infrared Survey Telescope, or WFIRST, which again people are calling
a successor to Hubble.
And that might actually be a little more accurate, since WFIRST will have the same primary mirror
size as Hubble: 2.4 meters.
But it has a key difference.
WFIRST is designed to view an incredibly wide field of view, 100 times more sky than Hubble
in a single observation.
Due for launch in 2025, WFIRST will head out to Sun-Earth Lagrange point L2, just like
James Webb.
And once again, because it’s an unstable place, it’ll only have station keeping fuel
for about 6 years.
The primary purpose of WFIRST is to scan the sky and help us understand the nature of dark
energy.
This is the all pervasive force that’s accelerating the expansion of the Universe.
Although astronomers know it’s there, they still have no idea what’s causing it.
Is the acceleration stable, or is it increasing, leading to a future Big Rip scenario in the
future?
In addition to studying dark energy, WFIRST will be equipped with a coronagraph, used
to block the light from stars, revealing the planets orbiting them.
The coronagraph is very clever, using a system of mirrors and masks to block the light from
stars and reveal the atmospheres of thousands of planets.
Unfortunately WFIRST won’t be able to study smaller exoplanets, just the larger Jupiter-like
worlds.
That is, on its own.
However, scientists are considering launching a flower-shaped coronagraph to serve as a
companion to WFIRST.
This would fly about 40,000 km away from WFIRST and perfectly block the light from a central
star, while allowing the light from the planet to sneak through.
With this configuration, it would be able to see the atmospheres of Earth-like worlds.
In other words, we’d be able to search for life directly.
We did a whole video on gravitational wave astronomy, and how astronomers have made their
first detections of colliding black holes last year.
This is an entirely new kind of astronomy, requiring a whole new set of tools.
There are several ground-based projects in the works, but to get the most sensitive observations,
the best place for a gravitational wave observatory will be in space… of course.
And this year, the European Space Agency announced their commitment to building such an observatory.
Known as the Laser Interferometer Space Antenna, or LISA, it’ll be a constellation of three
spacecraft, flying in formation in an equatorial triangle at a distance of 2.5 million kilometers
from each other.
The spacecraft will send precise laser pulses at each other, which will change in length
when a gravitational wave sweeps through the region.
From this, the satellites will be able to determine the direction and magnitude of the
event that generated the gravitational waves.
For example, LISA should be capable of detecting compact objects smashing into gether, like
white dwarfs and neutron stars, or the mergers of supermassive black holes, or black holes
orbiting around one another.
It’ll even be able to detect the gravitational wave background of the Universe, and how it
might have been affected by inflation and other events.
Unfortunately, we’re going to need to wait.
Currently, LISA isn’t scheduled to blast off until the 2030s.
But when it does become operational, we’ll see the Universe in an entirely new spectrum.
The science of gravitational wave astronomy will have a powerful tool at its disposal.
There, that’s three space-based supertelescopes coming.
There’s one more to go, and this one is going to be a monster.
I’ll explain it in a second, but first I’d like to thank:
Thomas Croley Daniel
And the rest of our 762 patrons for their generous support.
If you love what we’re doing and want to get in on the action, head over to patreon.com/universetoday.
I promise you, I have saved the best for last.
No question.
There’s a space-based mission in the works which is going to be the true spiritual successor
to Hubble.
But at a scale I can barely wrap my brain around.
It’s called the Large UV Optical Infrared Surveyor Telescope, or LUVOIR.
Right in the name, you see that it’s going to be able to view a huge chunk of the spectrum,
from infrared, through optical, and into the ultraviolet.
Just like Hubble.
But the size.
Wow.
LUVOIR is expected to be 15-18 meters in diameter.
Again, for comparison, Hubble is 2.4 meters.
LUVOIR will be bigger than any ground-based observatory we have here on Earth, matching
the super telescopes I mentioned last episode.
But again… it’ll be in space!
One idea is that LUVOIR will be launched to the Sun-Earth L2 point, like James Webb and
others.
But another is that it’ll go to the Earth-Moon Lagrange point, at the future Deep Space Gateway.
This would make it serviceable by astronauts, and it could then last for decades.
It will almost certainly be built with a coronagraph, to block the light from distant stars.
But in the case of LUVOIR, it’ll be able to directly resolve Earth-sized worlds in
the habitable zones of other stars.
What else will they do with a telescope this big?
Everything.
Like Hubble, LUVOIR will help to find the distribution of dark matter in the Universe,
measure dark matter, find newly forming planetary systems, and see the very first stars in the
Universe.
Unfortunately, we’re looking a long time into the future.
NASA is expected to make LUVOIR one if its top priorities in 2020, but it should still
take decades to finally launch.
We might have to wait until the late 2030s to see first light.
I can be patient.
This wraps up our two-parter on the new super telescopes.
I hope you’re as excited about these upcoming missions as I am.
And as each one gets first light, I’ll definitely keep you posted.
Good luck to everyone working on them.
What missions are you most excited about?
Let me know your thoughts in the comments.
I actually haven’t decided what my next video is going to be.
Probably something about supermassive black holes.
But do you have any topics you’d like me to dig into?
Let me know your thoughts in the comments.
It’s time for your playlist.
This time we start with an interview we did with Dr. Brad Peterson, all about the LUVOIR
telescope.
Then a video from NASA about the search for life, including some of these upcoming telescopes.
10 facts about the James Webb telescope, a video about WFIRST, and finally, a video about
LISA.
Enjoy.