4.18.24
Media Contacts
Ray Villard
villard@stsci.edu
Space Telescope Science Institute, Baltimore, Maryland
Bethany Downer
Bethany.Downer@esahubble.org
ESA/Hubble Chief Science Communications Officer
Science Contact
Pablo García Martín
Autonomous University of Madrid, Madrid, Spain
Wayward Asteroid Photobombs Hubble Snapshot of Galaxy UGC 12158
This Hubble Space Telescope image of the barred spiral galaxy UGC 12158 looks like someone took a white marking pen to it. In reality it is a combination of time exposures of a foreground asteroid moving through Hubble’s field-of-view, photobombing the observation of the galaxy. Several exposures of the galaxy were taken, what is evidence in the dashed pattern.
The asteroid appears as a curved trail due to parallax: because Hubble is not stationary, but orbiting Earth, and this gives the illusion that the faint asteroid is swimming along a curved trajectory. The uncharted asteroid is in inside the asteroid belt in our solar system, and hence is 10 trillion times closer to Hubble than the background galaxy.
Rather than a nuisance, this type of data are useful to astronomers for doing a census of the asteroid population in our solar system.
Image NASA, ESA, Pablo García Martín (UAM)
Image Processing Joseph DePasquale (STScI)
Size Distribution for Unknown Asteroids in Hubble Asteroid Hunter Survey
This graph is based on Hubble Space Telescope archival data that was used to identify a largely unseen population of very small asteroids in their tracks. The asteroids were not the intended targets, but instead photobombed background stars and galaxies in Hubble images. The comprehensive treasure hunt required perusing 37,000 Hubble images spanning 19 years. This was accomplished by using “citizen science” volunteers and artificial intelligence algorithms. The payoff was finding 1,701 asteroid trails of previously undetected asteroids. Illustration Pablo García Martín (UAM), Elizabeth Wheatley (STScI)
Asteroid Passes in Front of UGC 12158 (Compass Image)
This Hubble Space Telescope image of the barred spiral galaxy UGC 12158 looks like someone took a white marking pen to it. In reality it is a combination of time exposures of a foreground asteroid moving through Hubble’s field-of-view, photobombing the observation of the galaxy. Several exposures of the galaxy were taken, what is evidence in the dashed pattern.
The asteroid appears as a curved trail due to parallax: Hubble is not stationary, but orbiting Earth, and this gives the illusion that the faint asteroid is swimming along a curved trajectory. The uncharted asteroid is inside the asteroid belt in our solar system, and hence is 10 trillion times closer to Hubble than the background galaxy.
Rather than a nuisance, this type of data are useful to astronomers for doing a census of the asteroid population in our solar system.
Image NASA, ESA, Pablo García Martín (UAM)
Image Processing Joseph DePasquale (STScI)
Acknowledgment Alex Filippenko (UC Berkeley)
Summary
Deep-Sky Exposure Yields Telltale Evidence for Asteroid Moving Across the Celestial Background
Over 4 billion years ago, the eight major planets around our Sun formed by sweeping up debris from a vast disk of dust and gas surrounding the Sun. This is common to the planet birthing process, and the Hubble Space Telescope was the first to optically see similar disks surrounding newborn stars, providing a peek into the solar system’s formative years. Now, 4 billon years later, the planet construction yard is still cluttered with leftover debris.
Most of this ancient space rubble, called asteroids, can be found between the orbits of Mars and Jupiter within the main asteroid belt. The census of the asteroid population is ongoing. Hubble’s unique capabilities allow it to be used as an “asteroid hunter” for this task. Asteroids appear as curved trails in Hubble images. The trails are due to parallax because Hubble is not stationary, but orbiting Earth. This gives the illusion that the faint asteroids are swimming along curved trajectories.
The Hubble archives, spanning many years, are loaded with images that capture wayward asteroids trekking along their orbits. They were not the intended targets, but instead photobombed background stars and galaxies. Finding these asteroids is sort of a game of Where’s Waldo. It was recognized this would be a Herculean effort for any group of astronomers, so the researchers relied on a small army of volunteer citizen scientists to peruse the gaggle of Hubble photos. What they found was applied to machine learning to dig out even more asteroids. The project identified 1,701 asteroid trails. Most of the asteroids are too small to have been previously detected without Hubble’s sharp resolution and ultraviolet-light sensitivity.
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Like boulders, rocks, and pebbles scattered across a landscape, asteroids come in a wide range of sizes. Cataloging asteroids in space is tricky because they are faint and they don’t stop to be photographed as they zip along their orbits around the Sun.
Astronomers recently used a trove of archived images taken by NASA’s Hubble Space Telescope to visually snag a largely unseen population of smaller asteroids in their tracks. The treasure hunt required perusing 37,000 Hubble images spanning 19 years. The payoff was finding 1,701 asteroid trails, with 1,031 of the asteroids previously uncatalogued. About 400 of these uncatalogued asteroids are below 1 kilometer in size.
Volunteers from around the world known as “citizen scientists” contributed to the identification of this asteroid bounty. Professional scientists combined the volunteers’ efforts with machine learning algorithm to identify the asteroids. It represents a new approach to finding asteroids in astronomical archives spanning decades, which may be effectively applied to other datasets, say the researchers.
“We are getting deeper into seeing the smaller population of main belt asteroids. We were surprised with seeing such a large number of candidate objects,” said lead author Pablo García Martín of the Autonomous University of Madrid, Spain. “There was some hint of this population existing, but now we are confirming it with a random asteroid population sample obtained using the whole Hubble archive. This is important for providing insights into the evolutionary models of our solar system.”
The large, random sample offers new insights into the formation and evolution of the asteroid belt. Finding a lot of small asteroids favors the idea that they are fragments of larger asteroids that have collided and broken apart, like smashed pottery. This is a grinding-down process spanning billions of years.
An alternative theory for the existence of smaller fragments is that they formed that way billions of years ago. But there is no conceivable mechanism that would keep them from snowballing up to larger sizes as they agglomerated dust from the planet-forming circumstellar disk around our Sun. “Collisions would have a certain signature that we can use to test the current main belt population,” said co-author Bruno Merín of the European Space Astronomy Centre, in Madrid, Spain.
Amateur Astronomers Teach AI to Find Asteroids
Because of Hubble’s fast orbit around the Earth, it can capture wandering asteroids through their telltale trails in the Hubble exposures. As viewed from an Earth-based telescope, an asteroid leaves a streak across the picture. Asteroids “photobomb” Hubble exposures by appearing as unmistakable, curved trails in Hubble photographs.
As Hubble moves around the Earth, it changes its point of view while observing an asteroid, which also moves along its own orbit. By knowing the position of Hubble during the observation and measuring the curvature of the streaks, scientists can determine the distances to the asteroids and estimate the shapes of their orbits.
The asteroids snagged mostly dwell in the main belt, which lies between the orbits of Mars and Jupiter. Their brightness is measured by Hubble’s sensitive cameras. And comparing their brightness to their distance allows for a size estimate. The faintest asteroids in the survey are roughly one forty-millionth the brightness of the faintest star that can be seen by the human eye.
“Asteroid positions change with time, and therefore you cannot find them just by entering coordinates, because at different times, they might not be there,” said Merín. “As astronomers we don’t have time to go looking through all the asteroid images. So we got the idea to collaborate with over 10,000 citizen-science volunteers to peruse the huge Hubble archives.”
In 2019 an international group of astronomers launched the Hubble Asteroid Hunter, a citizen-science project to identify asteroids in archival Hubble data. The initiative was developed by researchers and engineers at the European Science and Technology Centre (ESTEC) and the European Space Astronomy Centre’s science data center (ESDC), in collaboration with the Zooniverse platform, the world’s largest and most popular citizen-science platform, and Google.
A total of 11,482 citizen-science volunteers, who provided nearly 2 million identifications, were then given a training set for an automated algorithm to identify asteroids based on artificial intelligence. This pioneering approach may be effectively applied to other datasets.
The project will next explore the streaks of previously unknown asteroids to characterize their orbits and study their properties, such as rotation periods. Because most of these asteroid streaks were captured by Hubble many years ago, it is not possible to follow them up now to determine their orbits.
The findings are published in the journal Astronomy and Astrophysics.
To learn how you can participate in citizen science projects related to NASA, visit https://science.nasa.gov/citizen-science/. Participation is open to everyone around the world, not limited to U.S. citizens or residents.
See the full article here.
Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct.
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The Space Telescope Science Institute (STScI) is the science operations center for the Hubble Space Telescope (HST).
The Hubble telescope was built by the United States space agency National Aeronautics Space Agency with contributions from the The European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganization](EU).
The Space Telescope Science Institute (STScI) selects Hubble’s targets and processes the resulting data, while the NASA Goddard Space Flight Center controls the spacecraft.
STScI is located on The Johns Hopkins University Homewood Campus in Baltimore, Maryland and was established in 1981 as a community-based science center that is operated for National Aeronautics Space Agency by The Assocation of Universities for Research in Astronomy (AURA). In addition to performing continuing science operations of HST and preparing for scientific exploration with JWST, STScI manages and operates the NASA Mikulski Archive for Space Telescopes, the Kepler Mission Data Resources in the Exoplanet Archive – NASA and a number of other activities benefiting from its expertise in and infrastructure for supporting the operations of space-based astronomical observatories.
Most of the funding for STScI activities comes from contracts with NASA’s Goddard Space Flight Center but there are smaller activities funded by NASA’s Ames Research Center, NASA’s Jet Propulsion Laboratory, and The European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganization](EU). The staff at STScI consists of scientists (mostly astronomers and astrophysicists), spacecraft engineers, software engineers, data management personnel, education and public outreach experts, and administrative and business support personnel. There are approximately 100 Ph.D. scientists working at STScI, 15 of which are ESA staff who are on assignment to the HST project. The total STScI staff consists of about 850 people as of 2021.
STScI operates its missions on behalf of NASA, the worldwide astronomy community, and to the benefit of the public. The science operations activities directly serve the astronomy community, primarily in the form of HST, and JWST observations and grants, but also include distributing data from other NASA missions, such as the FUSE: Far Ultraviolet Spectroscopic Explorer – NASA, Galaxy Evolution Explorer – Universe Missions – NASA JPL-Caltech and ground-based sky surveys.
The ground system development activities create and maintain the software systems that are needed to provide these services to the astronomy community. STScI’s public outreach activities provide a wide range of information, on-line media, and programs for formal educators, planetariums and science museums, and the general public. STScI also serves as a source of guidance to NASA on a range of optical and UV space astrophysics issues.
The STScI staff interacts and communicates with the professional astronomy community through a number of channels, including participation at the bi-annual meetings of the American Astronomical Society, publication of quarterly STScI newsletters and the STScI website, hosting user committees and science working groups, and holding several scientific and technical symposia and workshops each year. These activities enable STScI to disseminate information to the telescope user community as well as enabling the STScI staff to maximize the scientific productivity of the facilities they operate by responding to the needs of the community and of NASA.
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.
President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.
Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.
NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra,
Spitzer and associated programs, and now the NASA/ESA/CSA James Webb Space Telescope.
NASA shares data with various national and international organizations such as The Japan Aerospace Exploration Agency [国立研究開発法人宇宙航空研究開発機構](JP) and The European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne] [Europäische Weltraumorganization](EU).
