By Chris Skeldon 
NASA, ESA, P.J. Martin (Autonomous University of Madrid), J. Depascal(STScI)
It appears that someone took a NASA/ESA Hubble Space Telescope image of the barred spiral galaxy UGC 12158 and crossed out it with a white pen. In fact, it is a combination of several exposures of a foreground asteroid moving across Hubble's field of view, creating a “light bombardment” for observing the galaxy.
Recently, astronomers used a set of archival images taken by NASA and the European Space Agency's Hubble Space Telescope to visually reveal a somewhat unknown group of small asteroids.
The treasure hunt required the analysis of 37,000 Hubble Telescope images, over a period of 19 years.
The reward was the find 1701 pieces of music of asteroids, with 1,031 of these to be catalogued. About 400 copies, uncataloged, large size Less than 1 km.
Volunteers from all over the world, known as “Citizen scientists“, contributed to the identification of this group of asteroids. Professional scientists then combined the volunteers' efforts with machine learning algorithms to identify the asteroids.
The research results were presented in A condition Recently published in Astronomy and astrophysics.
This is the New approach To find asteroids in astronomical archives It extends for decadesThe researchers say it can be effectively applied to other data sets.
“We are deepening our observations of the population of small asteroids in the main belt. We were surprised to see such a large number of candidates.” Pablo Garcia Martina researcher at the Autonomous University of Madrid, Spain, and the lead author of the article.
“There were some Evidence of the existence of this populationA, but we now confirm this with a random sample of asteroids obtained using the entire Hubble archive. This is important for providing information about evolutionary models of our solar system.
The large random sample provides new insights into the formation and evolution of the asteroid belt. The discovery of many small asteroids supports this idea They are fragments of larger asteroids Which collided and crumbled like destroyed pottery, a Crushing process Which lasts billions of years.
An alternative theory for the existence of smaller fragments is that It formed this way billions of years ago. But there is no conceivable mechanism that would prevent it, like a snowball rolling down a hill, from getting larger and larger as it collects dust from the planet-forming oceanic disk around our sun.
“The collisions will have a certain signature that we can use to test the current population of the main belt,” the co-author said. Bruno MirrenFrom the European Space Astronomy Center in Madrid, Spain.
Because of Hubble's fast orbit around Earth, it can pick out stray asteroids by their tracks in the exposures it takes.
Through a ground-based telescope, the asteroid leaves a mark in the image; You Asteroids “light bomb” displayed by HubbleThey appear as unmistakable curved lines in images taken by the space telescope.
This chart is based on archival data from the Hubble Space Telescope, which was used to identify a largely unknown group of very small asteroids. Asteroids were not the intended targets, but rather background stars and galaxies in the Hubble images. The treasure hunt required analyzing 37,000 Hubble images over 19 years. To this end, “citizen science” volunteers and artificial intelligence algorithms were used. The reward was the discovery of 1,701 previously undiscovered asteroid tracks.
As Hubble orbits the Earth, Change your perspective While observing an asteroid it is also moving along its orbit.
By knowing Hubble's location during observation and measuring the curvature of the lines, scientists can do this Determine distances to asteroids And estimate the shapes of their orbits.
The asteroids imaged are Mostly in the main waistWhich is located between the orbits of Mars and Jupiter. for you Brightness is measured by cameras Hubble's sensitive sensors, and comparing its brightness to its distance allow an estimate of its size.
The weakest asteroids analyzed during the study are about Forty millionths – 1/(40 x 106) – of the brightness of the faint star Which can be seen by the human eye.
“The positions of asteroids change over time Therefore, it cannot be found by simply entering the coordinates, because it may not be there at different times.
“As astronomers, We don't have time to search In all images of the asteroid. That's why we had an idea Cooperating with more than 10,000 citizens “Volunteers to analyze Hubble's huge archives,” he added.
In 2019, an international group of astronomers launched a project Hubble is an asteroid huntera citizen science project to identify asteroids in archival Hubble data.
The initiative was developed by researchers and engineers from the European Science and Technology Center and the Scientific Data Center ESAC, in collaboration with Zooniverse, the largest and most popular citizen science platform In the world and with Google.
A total of 11,482 citizen volunteerswhich provided about two million identifications, then received a training set for an automated AI-based asteroid identification algorithm.
This pioneering approach can be effectively applied to other datasets.
The project will then Exploring asteroid hazards They were not previously known to characterize their orbits and study their properties, such as rotation periods.
Since most of these asteroid streaks were captured by Hubble many years ago, I can't follow them now To determine their orbits.
