Astronomers are always
looking for the next big thing
.
A few days ago, at a meeting of the American Astronomical Society, researchers packed a standing room only conference room to hear about a successor to
James Webb
, the 6.5-meter space telescope that began operate last year.
With the success of this technological feat, NASA is now planning an optical telescope that would be as big as the James Webb and would have a big new goal:
to search for signs of life on Earth-like planets
, perhaps in the early 2040s. .
Mark Clampin, director of NASA's astrophysics division, said the telescope's assembly is in its
early stages
.
But he assured that, like James Webb, it will be located at L2, a gravitational balance point
1.5 million kilometers from Earth
.
Unlike the James Webb, it will be designed for
robotic maintenance and upgrades
, which could allow it to operate for decades and improve over time.
And there's already a name for the telescope:
the Habitable Worlds Observatory (HWO)
.
Illustration of an exoplanet.
That will be the goal of the new HWO telescope.
Photo File
"I'm very, very excited to see it actually happen," says John O'Meara, chief scientist at the WM Keck Observatory, the observatory in Hawaii that houses two of the world's largest optical telescopes.
"The service capacity will be enormous
," adds Aki Roberge of NASA's Goddard Space Flight Center.
Essentially, Roberge explains, this new project is going to create a "mountaintop observatory on L2."
Like a telescope on Earth, the mirrors and structure can remain while increasingly sophisticated instruments are swapped out.
"It is the instruments that make the difference," explains the scientist.
An illustration of what NASA's new telescope could look like.
The telescope, in addition to doing general astrophysics, should be able to
detect signs of life on 25
nearby Earth-like exoplanets, the minimum needed to statistically confirm whether life is common in the galaxy.
The US agency will take a conservative approach to the new telescope, to
avoid the cost overruns and delays
that James Webb suffered at the time.
That project required many untested technologies, the refinement of which took longer than expected.
Artist's rendering of the James Webb Space Telescope, which became operational last year.
NASA photo
For the new telescope,
NASA will take advantage of technologies already developed or under development
, including segmented mirrors like the one used on James Webb and the Roman Observatory's coronagraph, an optical device inside the telescope that blocks light from a star so that exoplanets they fade away
It will also establish a Large Observatory Technology Maturation Program (GOMaP) to refine those technologies for the new telescope and do similar readiness work for
subsequent large observatories
.
For example, because the new telescope will work with optical light, which has shorter wavelengths than the infrared light captured by James Webb, the new observatory
will need much tighter control
over the shape of the mirror.
It will need to be perfectly shaped to the level of a picometer,
one millionth of a millionth of a meter
, compared to one billionth of a meter for James Webb.
The Pillars of Creation, one of the first images captured by the James Webb telescope.
NASA photo
He will also need to upgrade the Roman telescope's coronagraph, which can block light from a star 100 million times brighter than his planet.
The coronagraph will have to deal with stars that are
10 billion times brighter
.
One key will be
to suppress stray light
, which may require a cylindrical baffle around it, similar to the one around the Hubble telescope.
That would protect your mirror from micrometeorites like the ones that have already struck James Webb.
Each hole in the mirror due to a meteorite impact causes stray light.
Some astronomers argue that a monolithic mirror, which has fewer edges than a segmented one, would scatter less light.
But recent research suggests that coronagraphs can also work with segmented mirrors.
Specialists prefer a segmented design, which allows engineers to make the mirror larger if science requires it, without running into the space limitations of rockets.
look too
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