The Vera C. Rubin Observatory is under construction at Cerro Pachon, in Chile. This image shows construction progress in late 2019. The observatory should be able to spot interstellar objects like Oumuamua. Image Credit: Wil O'Mullaine/LSST .
Astronomers have discovered two known interstellar objects (ISO), ‘Oumuamua and 21/Borisov. But there could be thousands of these objects passing through the Solar System at any time. According to a new paper, the upcoming Vera Rubin Telescope will be a fantastic interstellar object hunter, and could possibly find up to 70 objects a year coming from other star systems.
Illustration of an interstellar object approaching our solar system. Credit: Rubin Observatory/NOIRLab/NSF/AURA/J. daSilva
Most of the comets we see in the sky were born in our solar system. They may have formed deep within the Oort cloud, and for some, it is their first visit to the inner solar system, but they are distinctly children of the Sun. We know of only two objects that came from beyond our solar system, Omuamua and Borisov. There are likely other interstellar objects visiting our solar system, we just haven’t found them. But that’s likely to change when Rubin Observatory comes online.
The Vera C. Rubin Observatory is under construction at Cerro Pachon, in Chile. This image shows construction progress in late 2019. The VCO should be able to spot interstellar objects like Oumuamua. Image Credit: Wil O'Mullaine/LSST CC BY-SA 4.0, https://en.wikipedia.org/w/index.php?curid=62504391
In a year (perhaps two), the Vera C. Rubin Observatory in Chile will become operational and commence its 10-year Legacy Survey of Space and Time (LSST). Using its 8.4-meter (27 foot) mirror and 3.2 gigapixel camera, this observatory is expected to collect 500 petabytes of images and data. It will also address some of the most pressing questions about the structure and evolution of the Universe and everything in it.
One of the highly-anticipated aspects of the LSST is how it will allow astronomers to locate and track interstellar objects (ISOs), which have become of particular interest since `Oumuamua flew through our system in 2017. According to a recent study by a team from the University of Chicago and the Harvard-Smithsonian Center for Astrophysics (CfA), the Rubin Observatory will detect around 50 objects during its 10-year mission, many of which we will be able to study up-close using rendezvous missions.
The Vera C. Rubin Observatory is under construction at Cerro Pachon, in Chile. This image shows construction progress in late 2019. The VCO should be able to spot interstellar objects like Oumuamua. Image Credit: Wil O'Mullaine/LSST CC BY-SA 4.0, https://en.wikipedia.org/w/index.php?curid=62504391
The Vera C. Rubin Observatory, formerly the Large Synoptic Survey Telescope (LSST), will commence operations sometime next year. Not wanting to let a perfectly good acronym go to waste, its first campaign will be known as the Legacy Survey of Space and Time (LSST). This ten-year survey will study everything from dark matter and dark energy to the formation of the Milky Way, and small objects in our Solar System.
According to a new study by Amir Siraj and Prof. Abraham Loeb of Harvard University, another benefit of this survey will be the discovery of interstellar objects that regularly enter the Solar Systems. These results, when combined with physical characterizations of the objects, will teach us a great deal about the origin and nature of planetary systems (and could even help us spot an alien probe or two!)
The complete focal plane of the future LSST Camera is more than 2 feet wide and contains 189 individual sensors that will produce 3,200-megapixel images. Crews at SLAC have now taken the first images with it. (Jacqueline Orrell/SLAC National Accelerator Laboratory)
The Vera C. Rubin Observatory has taken another step towards first light, projected for some time in 2022. Its enormous 3200 megapixel camera just took its first picture during lab testing at the SLAC National Accelerator Laboratory. The camera is the largest ever built, and its unprecedented power is the driving force behind the Observatory’s ten year Legacy Survey of Space and Time (LSST).
For some time now, astronomers have known that the majority of systems in our galaxy consist of binary pairs rather than individual stars. What’s more, in recent decades, research has revealed that stars like our Sun are actually born in clusters within solar nebulas. This has led to efforts in recent years to locate G-type (yellow dwarf) stars in our galaxy that could be the Sun’s long-lost “solar siblings.”
And now, a new study by Harvard astronomers Amir Siraj and Prof. Abraham Loeb has shown that the Sun may once have once had a very similar binary companion that got kicked out of our Solar System. If confirmed, the implications of this could be groundbreaking, especially where theories on how the Oort Cloud formed and whether or not our system captured a massive object (Planet Nine) in the past.
Artist's conception of accretion flares resulting from the encounter of an Oort-cloud comet and a hypothesized black hole in the outer solar system.
Credit: M. Weiss
A comet-eating black hole the size of a planet? It’s possible. And if there’s one out there in the distant Solar System, a pair of researchers think they know how to find it.
If they do, we might finally put the Planet 9 issue to rest.
One of the many PHOs (Potentially Hazardous Objects) that we're keeping an eye on. Image Credit: NASA
It is a well-known astronomical convention that Earth has only one natural satellite, which is known (somewhat uncreatively) as “the Moon”. However, astronomers have known for a little over a decade that Earth also has a population of what are known as “transient Moons”. These are a subset of Near-Earth Objects (NEOs) that are temporarily scooped up by Earth’s gravity and assume orbits around our planet.
According to a new study by a team of Finish and American astronomers, these temporarily-captured orbiters (TCOs) could be studied with the Large Synoptic Survey Telescope (LSST) in Chile – which is expected to become operational by 2020. By examining these objects with the next-generation telescope, the study’s authors argue that we stand to learn a great deal about NEOs and even begin conducting missions to them.
Artist's impression of Oumuamua leaving the Solar System. Credit: NASA
On October 19th, 2017, the Panoramic Survey Telescope and Rapid Response System-1 (Pan-STARRS-1) in Hawaii announced the first-ever detection of an interstellar object, named 1I/2017 U1 (aka. ‘Oumuamua). In the months that followed, multiple follow-up observations were conducted to learn more about this visitor, as well as resolve the dispute about whether it was a comet and an asteroid.
Rather than resolving the dispute, additional observations only deepened the mystery, even giving rise to suggestions that it might be an extra-terrestrial solar sail. For this reason, scientists are very interested in finding other examples of ‘Oumuamua-like objects. According to a recent study by a team of Harvard astrophysicists, it is possible that interstellar objects enter our system and end up falling into in our Sun somewhat regularly.
Artist's impression of a Near-Earth Asteroid passing by Earth. Credit: ESA
Roughly 4.5 billion years ago, scientists theorize that Earth experienced a massive impact with a Mars-sized object (named Theia). In accordance with the Giant Impact Hypothesis, this collision placed a considerable amount of debris in orbit, which eventually coalesced to form the Moon. And while the Moon has remained Earth’s only natural satellite since then, astronomers believe that Earth occasionally shares its orbit with “mini-moons”.
These are essentially small and fast-moving asteroids that largely avoid detection, with only one having been observed to date. But according to a new study by an international team of scientists, the development of instruments like the Large Synoptic Survey Telescope (LSST) could allow for their detection and study. This, in turn, will present astronomers and asteroid miners with considerable opportunities.
The study which details their findings recently appeared in the Frontiers in Astronomy and Space Sciences under the title “Earth’s Minimoons: Opportunities for Science and Technology“. The study was led by Robert Jedicke, a researcher from the University of Hawaii at Manoa, and included members from the Southwest Research Institute (SwRI), the University of Washington, the Luleå University of Technology, the University of Helsinki, and the Universidad Rey Juan Carlos.
As a specialist in Solar System bodies, Jedicke has spent his career studying the orbit and size distributions of asteroid populations – including Main Belt and Near Earth Objects (NEOs), Centaurs, Trans-Neptunian Objects (TNOs), comets, and interstellar objects. For the sake of their study, Jedicke and his colleagues focused on objects known as temporarily-captured orbiters (TCO) – aka. mini-moons.
These are essentially small rocky bodies – thought to measure up to 1-2 meters (3.3 to 6.6 feet) in diameter – that are temporarily gravitationally bound to the Earth-Moon system. This population of objects also includes temporarily-captured flybys (TCFs), asteroids that fly by Earth and make at least one revolution of the planet before escaping orbit or entering our atmosphere.
As Dr. Jedicke explained in a recent Science Dailynews release, these characteristics is what makes mini-moons particularly hard to observe:
“Mini-moons are small, moving across the sky much faster than most asteroid surveys can detect. Only one minimoon has ever been discovered orbiting Earth, the relatively large object designated 2006 RH120, of a few meters in diameter.”
This object, which measured a few meters in diameter, was discovered in 2006 by the Catalina Sky Survey (CSS), a NASA-funded project supported by the Near Earth Object Observation Program (NEOO) that is dedicated to discovering and tracking Near-Earth Asteroids (NEAs). Despite improvements over the past decade in ground-based telescopes and detectors, no other TCOs have been detected since.
Artist rendering of the LSST observatory (foreground) atop Cerro Pachón in Chile. Credit: Large Synoptic Survey Telescope Project Office.
After reviewing the last ten years of mini-moon research, Jedicke and colleagues concluded that existing technology is only capable of detecting these small, fast moving objects by chance. This is likely to change, according to Jedicke and his colleagues, thanks to the advent of the Large Synoptic Survey Telescope (LSST), a wide-field telescope that is currently under construction in Chile.
Once complete, the LSST will spend the ten years investigating the mysteries of dark matter and dark energy, detecting transient events (e.g. novae, supernovae, gamma ray bursts, gravitational lensings, etc.), mapping the structure of the Milky Way, and mapping small objects in the Solar System. Using its advanced optics and data processing techniques, the LSST is expected to increase the number of cataloged NEAs and Kuiper Belt Objects (KBOs) by a factor of 10-100.
But as they indicate in their study, the LSST will also be able to verify the existence of TCOs and track their paths around our planet, which could result in exciting scientific and commercial opportunities. As Dr. Jedicke indicated:
“Mini-moons can provide interesting science and technology testbeds in near-Earth space. These asteroids are delivered towards Earth from the main asteroid belt between Mars and Jupiter via gravitational interactions with the Sun and planets in our solar system. The challenge lies in finding these small objects, despite their close proximity.”
Time-lapse photo of the sky above the LSST construction site in Chile. Credit: LSST
When it is completed in a few years, it is hoped that the LSST will confirm the existence of mini-moons and help track their orbits around Earth. This will be possible thanks to the telescope’s primary mirror (which measures 8.4 meters (27 feet) across) and its 3200 megapixel camera – which has a tremendous field of view. As Jedicke explained, the telescope will be able to cover the entire night sky more than once a week and collect light from faint objects.
With the ability to detect and track these small, fast objects, low-cost missions may be possible to mini-Moons, which would be a boon for researchers seeking to learn more about asteroids in our Solar System. As Dr Mikael Granvik – a researcher from the Luleå University of Technology, the University of Helsinki, and a co-author on the paper – indicated:
“At present we don’t fully understand what asteroids are made of. Missions typically return only tiny amounts of material to Earth. Meteorites provide an indirect way of analyzing asteroids, but Earth’s atmosphere destroys weak materials when they pass through. Mini-moons are perfect targets for bringing back significant chunks of asteroid material, shielded by a spacecraft, which could then be studied in detail back on Earth.”
As Jedicke points out, the ability to conduct low-cost missions to objects that share Earth’s orbit will also be of interest to the burgeoning asteroid mining industry. Beyond that, they also offer the possibility of increasing humanity’s presence in space.
“Once we start finding mini-moons at a greater rate they will be perfect targets for satellite missions,” he said. “We can launch short and therefore cheaper missions, using them as testbeds for larger space missions and providing an opportunity for the fledgling asteroid mining industry to test their technology… I hope that humans will someday venture into the solar system to explore the planets, asteroids and comets — and I see mini-moons as the first stepping stones on that voyage.”
