First research flight images from innovative balloon-borne telescope
IMAGE: A FALSE-COLOUR IMAGE TAKEN BY THE SUPERBIT TELESCOPE SOON AFTER LAUNCH IN VISIBLE AND ULTRA-VIOLET LIGHT OF THE "TARANTULA NEBULA” - A NEIGHBOURHOOD OF THE LARGE MAGELLANIC CLOUD WHERE NEW STARS ARE BEING BORN. view more
CREDIT: SUPERBIT
Astronomers have successfully launched a balloon-borne telescope which has begun capturing images of the Universe on its first research flight.
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 where it will help researchers investigate the mystery of dark matter.
SuperBIT is a collaboration between Durham University, UK, the University of Toronto, Canada, Princeton University, USA, and NASA.
It launched from Wānaka, New Zealand (Aotearoa) earlier this week, following a two-year delay due to the Covid pandemic.
Carried by seasonally stable winds for about three months, it 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 33.5km altitude, above 99.5 per cent of the Earth’s atmosphere. It takes high-resolution images like those of the Hubble Space Telescope, but with a wider field of view.
The science goal for this first flight is to measure the properties of dark matter, a heavy but invisible type of material. Dark matter is all around us but poorly understood.
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 about dark matter suggest that, during a collision, some dark matter might either slow down, spread out, or get chipped off.
The researchers say that if they can map dark matter leaving the collision, they could finally start to learn what it is made of.
Professor Richard Massey, of Durham University’s Department of Physics, said: “It takes the gravity from an entire galaxy to move dark matter and SuperBIT will look at clusters of galaxies that happen to be colliding with each other.
“Essentially, we’re using the largest particle accelerators in the Universe, to smash lumps of dark matter and see where the bits fly.
“If dark matter goes ‘crunch’, or if bits are chipped off, we could finally start to learn what it’s made of.”
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 have to 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.
A false-colour image taken by the SuperBIT telescope soon after launch in visible and ultra-violet light of a pair of galaxies smashing into each other. As they collide, the “Antennae galaxies” NGC 4038 and NGC 4039 are ripping strips off each other and opening themselves for inspection.
CREDIT
SuperBIT
SuperBIT is the first ever balloon-borne telescope capable of taking wide-field images with resolution limited only by the laws of optics.
During its final test flight in 2019, SuperBIT demonstrated extraordinary pointing stability, with variation of less than one thirty-six thousandth of a degree for more than an hour.
SuperBIT cost about $5million/£4.1million, 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.
Reusable spacecraft can also be reconfigured and upgraded. For example, the development team buy a new camera shortly before each launch, because modern detectors are improving so rapidly. Using cutting-edge technology has kept SuperBIT young.
The team already has funding to upgrade SuperBIT’s 0.5 metre aperture 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 space telescopes to offer time to astronomers around the world.
The public can follow SuperBIT’s flight status on NASA’s website here.
Funding for the SuperBIT mission has been provided by NASA, the Canadian Space Agency, and the Royal Society.
ENDS
The SuperBIT telescope nestled among its solar panels and communications antennae. Picked up at dawn, ready to be carried to the launch pad beside the runway at Wānaka airport.
CREDIT
Richard Massey.
CAPTION
The international SuperBIT science team will return to their homes after launch. Members from Canada, USA, UK and Australia will monitor the telescope from different time zones for the next 100 days.
CREDIT
SuperBIT science team
Asteroid’s comet-like tail Is not made of dust, solar observatories reveal
Scientists thought asteroid Phaethon, which is the source of the Geminid meteor shower, was shedding dust to form a comet-like tail, but NASA solar observatories show the tail isn't dusty.
Peer-Reviewed PublicationIMAGE: THIS ILLUSTRATION DEPICTS ASTEROID PHAETHON BEING HEATED BY THE SUN. THE ASTEROID’S SURFACE GETS SO HOT THAT SODIUM INSIDE PHAETHON’S ROCK LIKELY VAPORIZES AND VENTS INTO SPACE, CAUSING IT TO BRIGHTEN LIKE A COMET AND FORM A TAIL. view more
CREDIT: NASA/JPL-CALTECH/IPAC
A weird asteroid has just gotten a little weirder.
We have known for a while that asteroid 3200 Phaethon acts like a comet. It brightens and forms a tail when it’s near the Sun, and it is the source of the annual Geminid meteor shower, even though comets are responsible for most meteor showers. Scientists had blamed Phaethon’s comet-like behavior on dust escaping from the asteroid as it’s scorched by the Sun. However, a new study using two NASA solar observatories reveals that Phaethon’s tail is not dusty at all but is actually made of sodium gas.
“Our analysis shows that Phaethon’s comet-like activity cannot be explained by any kind of dust,” said California Institute of Technology PhD student Qicheng Zhang, who is the lead author of a paper published in the Planetary Science Journal reporting the results.
Asteroids, which are mostly rocky, do not usually form tails when they approach the Sun. Comets, however, are a mix of ice and rock, and typically do form tails as the Sun vaporizes their ice, blasting material off their surfaces and leaving a trail along their orbits. When Earth passes through a debris trail, those cometary bits burn up in our atmosphere and produce a swarm of shooting stars – a meteor shower.
After astronomers discovered Phaethon in 1983, they realized that the asteroid’s orbit matched that of the Geminid meteors. This pointed to Phaethon as the source of the annual meteor shower, even though Phaethon was an asteroid and not a comet.
In 2009, NASA’s Solar Terrestrial Relations Observatory (STEREO) spotted a short tail extending from Phaethon as the asteroid reached its closest point to the Sun (or “perihelion”) along its 524-day orbit. Regular telescopes hadn’t seen the tail before because it only forms when Phaethon is too close to the Sun to observe, except with solar observatories. STEREO also saw Phaethon’s tail develop on later solar approaches in 2012 and 2016. The tail’s appearance supported the idea that dust was escaping the asteroid’s surface when heated by the Sun.
However, in 2018, another solar mission imaged part of the Geminid debris trail and found a surprise. Observations from NASA’s Parker Solar Probe showed that the trail contained far more material than Phaethon could possibly shed during its close approaches to the Sun.
Zhang’s team wondered whether something else, other than dust, was behind Phaethon’s comet-like behavior. “Comets often glow brilliantly by sodium emission when very near the Sun, so we suspected sodium could likewise serve a key role in Phaethon’s brightening,” Zhang said.
An earlier study, based on models and lab tests, suggested that the Sun’s intense heat during Phaethon’s close solar approaches could indeed vaporize sodium within the asteroid and drive comet-like activity.
Hoping to find out what the tail is really made of, Zhang looked for it again during Phaethon’s latest perihelion in 2022. He used the Solar and Heliospheric Observatory (SOHO) spacecraft — a joint mission between NASA and the European Space Agency (ESA) – which has color filters that can detect sodium and dust. Zhang’s team also searched archival images from STEREO and SOHO, finding the tail during 18 of Phaethon’s close solar approaches between 1997 and 2022.
In SOHO’s observations, the asteroid’s tail appeared bright in the filter that detects sodium, but it did not appear in the filter that detects dust. In addition, the shape of the tail and the way it brightened as Phaethon passed the Sun matched exactly what scientists would expect if it were made of sodium, but not if it were made of dust.
This evidence indicates that Phaethon’s tail is made of sodium, not dust.
“Not only do we have a really cool result that kind of upends 14 years of thinking about a well-scrutinized object,” said team member Karl Battams of the Naval Research Laboratory, “but we also did this using data from two heliophysics spacecraft – SOHO and STEREO – that were not at all intended to study phenomena like this.”
Zhang and his colleagues now wonder whether some comets discovered by SOHO – and by citizen scientists studying SOHO images as part of the Sungrazer Project – are not comets at all.
“A lot of those other sunskirting ‘comets’ may also not be ‘comets’ in the usual, icy body sense, but may instead be rocky asteroids like Phaethon heated up by the Sun,” Zhang explained.
Still, one important question remains: If Phaethon doesn’t shed much dust, how does the asteroid supply the material for the Geminid meteor shower we see each December?
Zhang’s team suspects that some sort of disruptive event a few thousand years ago – perhaps a piece of the asteroid breaking apart under the stresses of Phaethon’s rotation – caused Phaethon to eject the billion tons of material estimated to make up the Geminid debris stream. But what that event was remains a mystery.
More answers may come from an upcoming Japan Aerospace Exploration Agency (JAXA) mission called DESTINY+ (short for Demonstration and Experiment of Space Technology for Interplanetary voyage Phaethon fLyby and dUst Science). Later this decade, the DESTINY+ spacecraft is expected to fly past Phaethon, imaging its rocky surface and studying any dust that might exist around this enigmatic asteroid.
by Vanessa Thomas
NASA’s Goddard Space Flight Center, Greenbelt, Md.
JOURNAL
The Planetary Science Journal
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Sodium Brightening of (3200) Phaethon near Perihelion
ARTICLE PUBLICATION DATE
25-Apr-2023
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