Posted by KeighleyAstro on Jan 31, 2022 in Main |

It was a welcome return visit By Dr Sue Bowler from the University of Leeds at the First society meeting of 2022.

The title of her presentation was titled ‘The Next big thing’. The subject matter was the James Webb Space telescope and the line up of future telescopes to be based in space and on the Earth.

Dr Bowler explained that the James Webb Space Telescope was a decade late and $10 billion over budget, but it has finally launched.
Now that the telescope is in space, what’s next for astrophysics. De Bowler outlined the future missions to get excited about.

With the successful Christmas day launch of NASA’s James Webb Space Telescope (JWST), NASA and its partners have finally secured JWST’s place as a worthy successor to the 30-year-old Hubble space telescope. It should rewrite the history of almost everything we know about the cosmos; from the universe’s first light to what we know about the outer fringes of our own solar system.
Following six months of commissioning including focusing the mirrors, testing the instruments, calibration, and other operational tasks that need to be verified, NASA expects to have the first science images and spectra from the telescope by next summer.

Beyond the early release observations, full science operations will include both data that have no proprietary period (early release science programs as well as some of the Guaranteed time observation programs) that will be released almost immediately.

The Webb remains the largest space telescope ever built and its deployable mirror stretches more than 21 feet in diameter, and is composed of 18 hexagonal, gold-plated beryllium mirror segments. But unlike Hubble, it will operate near the Earth–Sun L2 (Lagrange point), a point of gravitational equilibrium, some 1.5 million km beyond earth’s orbit. And unlike Hubble, once the Webb telescope reaches its final observing position at L2, it won’t be able to be serviced.

It’s scheduled for a five-year baseline mission, but NASA has reported that after a very precise launch and the completion of two mid-course trajectory manoeuvres, there’s more propellant left than initially envisaged. This should allow for science operations for more than 10 years.

Nancy Grace Roman Telescope

This telescope, named after Nancy Grace Roman, NASA’s first chief astronomer; was originally called the Wide-Field Infrared Space Telescope, or WFIRST. Its main purpose will be to map large swaths of the universe to study dark energy.
(The original name is also a clever play on words: In the mathematical equations that cosmologists use to describe dark energy, its equation of state, or relationship between pressure and density, is represented by “w.” Because the point of the mission is to study dark energy, “w” comes first — hence the name WFIRST.)

Expected to launch in 2027, the telescope will survey millions of galaxies, building a map of our cosmological neighbourhood. Astronomers hope to use the distribution of galaxies to tease out the evolution of dark energy. As a bonus, the instrument will also use gravitational microlensing (tiny changes in background starlight) to discover potentially millions of exoplanets.

LUVOIR

The James Webb Space Telescope is like a souped-up version of the Hubble Space Telescope. It’s so big that it can’t even fit into a single rocket fairing without a really complicated, origami-like folding of its mirror segments.

The Large Ultraviolet/Optical/Infrared Surveyor (LUVOIR) is even bigger, with a mirror diameter of about 50 feet (over 15 meters). Astronomers hope this general-purpose telescope could achieve a variety of astronomical science objectives, such as observe the cloud tops of Jupiter with a 15-mile (25 kilometers) resolution and hunt for biosignatures in the atmospheres other planets.
LUVOIR is only in the design phase and is competing with other observatories for priority funding. But if it goes through, the mega space telescope will launch sometime in the 2030s.

HabEx

Finding habitable planets is a pretty hot topic in astronomy. The discovery of an Earth 2.0 would be a gold mine, helping us understand how common life is in the universe, and maybe even heralding a discovery that we’re not alone. To do that, astronomers search for near copies of Earth. Planets with similar masses and compositions to our home world orbiting sunlike stars at just the right distance to allow for liquid water.

But finding the planet is only the beginning; we need to study its atmosphere, looking for biosignatures, which are chemical byproducts of life. An abundance of oxygen, for example, might be a sign that photosynthesis is active on that world, and a lot of methane might show us that there are bacteria-like organisms there.

The Habitable Exoplanet Imaging Mission (HabEx) hopes to do just that. Although it, too, is competing for funding, proponents hope to launch HabEx in 2035. What makes HabEx shine is its star shade, a massive flying disc that would block the light of individual stars, allowing the telescope to directly image exoplanets.

LISA

The Laser Interferometer Space Antenna (LISA) is a space-based gravitational wave observatory. Led by the European Space Agency, it will target gravitational wave sources that ground-based detectors can’t, like colliding supermassive black holes and the mergers of compact objects within our own galaxy.

LISA is a formation of three satellites, all orbiting the sun together while maintaining a separation of about 1.5 miles (2.5 million km).

By continually bouncing lasers between them, the satellites can measure any slight changes to their distance, especially if gravitational waves come washing through. The observatory is targeted for launch in 2034.

DARE

There was a time before stars. The first few hundred million years after the Big Bang were appropriately named the “Dark Ages.” This era has not been observed with any telescope … because, well, it was dark explained Dr Bowler.

But floating through that darkness were tendrils of neutral hydrogen. Neutral hydrogen gives off a very particular sort of radiation, emitting light at precisely 2.1 centimetres. That radiation has sailed through the universe over all these eons and today, 13 billion years later, has redshifted to have a wavelength of around 2 meters (6.6 feet).

That’s in the radio spectrum, which means any attempts to detect this sort of radiation are overwhelmed by our terrestrial radio chatter. So that’s where the Dark Ages Radio Explorer (DARE) comes in.

DARE is currently in the design phase, and proponents hope to launch it sometime in the next few years. It’s a relatively simple observatory, basically a car antenna in space, but its location will be unique: It will orbit the moon. The far side of the moon is the only known place in the inner solar system known to be free of human-generated radio interference. It’s the quietest place nearby, and the best place to hunt for the cosmic Dark Ages.

Vera C Rubin Observatory

The Vera C Rubin Observatory in Chile, also known as the Large Synoptic Survey Telescope (LSST) will have first light by 2023.
Its primary goal will be to complete the Legacy Survey of Space and Time (LSST) using its wide-field reflecting telescope and its 27.5ft mirror.
It will photograph the entire available sky every few nights to get a broad view of all the planets, stars, moons and asteroids as they move across the sky.
The observatory has been named after American astronomer Vera Rubin who pioneered the discovery of galaxy rotation rates and dark matter.
The telescope design has a very wide field of view, up to 3.5 degrees in diameter, or 9.6 square degrees.
The Sun and the Moon when viewed from the Earth have a 0.5 degree diameter, or 0.3 square degrees.
This wide field view, combined with the large aperture, gives it a large view of the night sky, more than three times the best existing telescopes.
The primary mirror is 28ft in diameter, its second mirror is 11.2ft in diameter and it has a third ring-like mirror 16ft in diameter.

This is the natural successor of a long tradition of full sky surveys that started in the 18th century with compilations such as the Messier catalog.
The telescope within the observatory will be named the Simonyi Survey Telescope, to acknowledge the private donors Charles and Lisa Simonyi.
There is some concern large satellite constellations like SpaceX Starlink and OneWeb could impact the wide field camera by up to 50%.
As well as campaigning to reduce the brightness of telescopes, AI can be used to make allowances for the telescopes based on their accurate positions.
The Vera C Rubin Observatory and the Simonyi Survey Telescope will finish construction this year, with first light in 2022 or 2023.

Extremely Large Telescope

The Extremely Large Telescope is currently under construction. When completed, it is planned to be the world’s largest optical/near inferred extremely large telscope. Part of the European Southern Observatory (ESO) agency, it is located on top of Cerro Armazones in the Atacama Desert of northern Chile.

The design consists of a reflecting telescope with a 39.3-metre-diameter (130-foot) segmented primary mirror and a 4.2 m (14 ft) diameter secondary mirror, and will be supported by adaptive optics, eight laser guide star units and multiple large science instruments. The observatory aims to gather 100 million times more light than the human eye, 13 times more light than the largest optical telescopes existing in 2014, and be able to correct for atmospheric distortion. It has around 256 times the light gathering area of the Hubble Space Telescope and, according to the ELT’s specifications, would provide images 16 times sharper than those from Hubble.

The project was originally called the European Extremely Large Telescope (E-ELT), but the name was shortened in 2017. The ELT is intended to advance astrophysical knowledge by enabling detailed studies of planets around other stars, the first galaxies in the Universe, supermassive black holes, and the nature of the Universe’s dark sector, and to detect water and organic molecules in protoplanetary disks around other stars. The facility is expected to take 11 years to construct, from 2014 to 2025.

On 11th June 2012, the ESO Council approved the ELT programme’s plans to begin civil works at the telescope site, with construction of the telescope itself pending final agreement with governments of some member states. Construction work on the ELT site started in June 2014. By December 2014, ESO had secured over 90% of the total funding and authorized construction of the telescope to start, which will cost around one billion euros for the first construction phase. The first stone of the telescope was ceremonially laid on 26 May 2017, initiating the construction of the dome’s main structure and telescope, with first light being planned for 2027.

The ELT will search for extrasolar planets; planets orbiting other stars. This will include not only the discovery of planets down to Earth-like masses through indirect measurements of the wobbling motion of stars perturbed by the planets that orbit them, but also the direct imaging of larger planets and possibly even the characterisation of their atmospheres. The telescope will attempt to image Earthlike exoplanets, which may be possible.

Furthermore, the ELT’s suite of instruments will allow astronomers to probe the earliest stages of the formation of planetary systems and to detect water and organic molecules in protoplanetary discs around stars in the making. Thus, the ELT will answer fundamental questions regarding planet formation and evolution.
By probing the most distant objects the ELT will provide clues to understanding the formation of the first objects that formed: primordial stars, primordial galaxies and black holes and their relationships. Studies of extreme objects like black holes will benefit from the power of the ELT to gain more insight into time-dependent phenomena linked with the various processes at play around compact objects.

The ELT is designed to make detailed studies of the first galaxies. Observations of these early galaxies with the ELT will give clues that will help understand how these objects form and evolve. In addition, the ELT will be a unique tool for making an inventory of the changing content of the various elements in the Universe with time, and to understand star formation history in galaxies.

One of the goals of the ELT is the possibility of making a direct measurement of the acceleration of the Universe’s expansion. Such a measurement would have a major impact on our understanding of the Universe. The ELT will also search for possible variations in the fundamental physical constants with time. An unambiguous detection of such variations would have far-reaching consequences for our comprehension of the general laws of physics.