University Of Toronto Astronomers Launch Balloon-borne Telescope

Astronomers have successfully launched a balloon-borne telescope that has begun capturing images of the universe on its first flight above the Earth’s atmosphere.

The Super Pressure Balloon-Borne Imaging Telescope (SuperBIT) was flown to the edge of space by a helium-filled NASA scientific balloon the size of a football stadium. There, it will help researchers investigate the mystery of dark matter.

SuperBIT has already taken its first images on this flight, showing the “Tarantula Nebula” – a bright cluster of gas and dust in a galaxy neighbourhood near our Milky Way – and the collision between the two galaxies NGC 4038 and NGC 4039, known as “the Antennae.”

SuperBIT is a collaboration between the University of Toronto, Princeton University, Durham University and NASA.

“A dedicated team of students developing one of the world’s great telescopes – it’s inspiring,” says Barth Netterfield, a professor in U of T’s David A. Dunlap department of astronomy and astrophysics and the department of physics in the Faculty of Arts & Science, and an associate at the Dunlap Institute for Astronomy and Astrophysics.

“After a decade of tremendous effort, we are getting these exquisite images with a wide range of science goals, which will help us to better understand the universe.”

The balloon aunched from Wānaka, New Zealand earlier this week, following a two-year delay due to the COVID pandemic.

Carried by seasonally stable winds for about three months, SuperBIT will circumnavigate the southern hemisphere several times – imaging the sky all night, then using solar panels to recharge its batteries during the day.

SuperBIT flies at an altitude of 33.5 kilometres, above 99.5 per cent of the Earth’s atmosphere. It takes high-resolution images like those from the Hubble Space Telescope, but with a much wider field of view.

The scientific goal for the first flight is to measure the properties of dark matter, a heavy but invisible type of material.

SuperBIT will test whether dark-matter particles can bounce off each other, by mapping the dark matter around clusters of galaxies that are colliding with neighbouring galaxy clusters.

Various theories suggest that some dark matter might either slow down, spread out, or get chipped off during a collision.

Although dark matter is invisible, SuperBIT will map where it is by the way it bends passing rays of light – a technique known as gravitational lensing.

While telescopes on the ground must squint through the Earth’s atmosphere – meaning their view can become blurred – space-based telescopes get a clear view of the light that has travelled billions of years from the distant universe.

SuperBIT is the first balloon-borne telescope capable of taking wide-field images – its sharpness of vision is not affected by the atmosphere, but only by the laws of optics.

During its final test flight in 2019, SuperBIT demonstrated extraordinary pointing stability.

“Imagine you’re trying to thread a needle that’s 2.5 kilometres away – so roughly 30 city blocks,” explains Emaad Paracha, a PhD candidate in the department of physics.

“SuperBIT has the ability to point to the exact spot you’d need that needle to be thread, while keeping that thread from touching the sides of the needle for up to 60 minutes.”

SuperBIT cost about US$5 million – almost 1,000 times less than an equivalent satellite. Not only is helium cheaper than rocket fuel, but the ability of SuperBIT to return to Earth via parachute meant the team could tweak its design over several test flights.

“A successful SuperBIT launch paves the way to a future in which individual academic institutions are able to design, develop and operate world-class space instruments at a low cost, while also providing the training opportunity for instrument development and data analysis for the students,” says Ajay Gill, a PhD candidate at the David A. Dunlap department of astronomy and astrophysics and the Dunlap Institute.

SuperBIT can also be upgraded on a regular basis. For example, the development team buys a new camera shortly before each launch, because modern detectors are improving so rapidly.

The team already has funding to upgrade SuperBIT’s 0.5-metre telescope to 1.6 metres, which would boost light gathering power tenfold, with a wider-angle lens and more megapixels.

The relatively cheap cost may even make it possible for a fleet of balloon-borne telescopes to offer time to astronomers around the world. Interested members of the public can track SuperBIT’s flight status on NASA’s website.

The mission was funded by NASA, the Canadian Space Agency, the Royal Society and U of T’s Dunlap Institute for Astronomy and Astrophysics.