Worlds arent the only celestial things with moons– asteroids can have them too. The new four-body system makes complicated gravitational problems like the three-body issue look basic by contrast.
The asteroid with many hangers-on is known as (130) Elektra. Initially found in 1873 by Christian Peters, it measured about 200 km in size and weighs roughly 7 x 10 ^ 18 kg. Thats more than enough mass to catch its three orbiting smaller sized asteroids, called S/2003 (130) 1, S/2014 (130) 1, and S/2014 (130) 2– the most current discovery was just detailed in a paper published on arXiv on February 10th..
Planets arent the only celestial objects with moons– asteroids can have them too. Image of (130) Elektra with the asteroids “halo” eliminated. Another potential detection of the moon around Elektra in a different data set– this one was gathered in 2019. Reducing the amount of data while evaluating it may seem counter-intuitive, however information decrease pipelines are prevalent in spectrography. To get rid of these artifacts, Dr. Berdeu and his group used a novel data reduction strategy for the SPHERE instrument called Projection, Interpolation, Convolution (PIC) and published in a separate paper back in 2020.
Picture of (130) Elektra with the asteroids “halo” removed. Credit: Berdeu et al
. Their designations reflect the year they were very first observed, which reveals that S/2014( 130) 2 sat unobserved in a dataset for over seven years. That dataset was gathered by the Spectro-Polarimetric High-contrast Exoplanet REsearch facility (SPHERE), an observing platform on the Very Large Telescope (VLT). The telescope turned its attention to (130) Elektra back in 2014. Over that time, the dataset caught S/2014 (130) 2 one hundred and twenty different times over 22 days. Why was it so hard to find?
Projected orbits of Elektras three moons. Credit: Berdeu et al
. There are two answers to that question. First, the overall quantity of data has actually to be minimized. Second, even when the information was minimized, the signal for the moon itself was concealed in the larger asteroids “halo.” Dr. Anthony Berdeu and his team established novel algorithms for both that allowed them to tease out the formerly indiscernible moon.
Another possible detection of the moon around Elektra in a different data set– this one was collected in 2019. Credit: Berdeu et al
. Lowering the quantity of information while examining it might seem counter-intuitive, but data reduction pipelines are prevalent in spectrography. Because information sets have actually optical artifacts derived from other spectra that arent always of interest to specific research studies, this is generally. To get rid of these artifacts, Dr. Berdeu and his group made use of a novel data reduction strategy for the SPHERE instrument called Projection, Interpolation, Convolution (PIC) and published in a separate paper back in 2020. With this tool, they could get rid of enough spectral artifacts to get a clearer photo of their intended target.
That target was still surrounded by a “halo,” which is another kind of spectral artifact that made the asteroids surface appear to glow. It likewise reached far enough out of the asteroids surface area to engulf S/2014( 130) 2, which has a semi-major axis of just 344 kilometers from Elektras surface.
Moons can take place anywhere as talked about in this UT video.
So the scientists developed another signal processing algorithm, which attempted to model the physics of the halo, and then get rid of those designed light levels from any captured picture of the target. Using an algorithm known as a point spread function (PSF), the scientists had the ability to successfully remove the halo effect from the asteroid, revealing Elektras tiniest and most closely orbiting satellite.
Hearteningly, this data reduction and halo removal strategy can be used on other asteroid observations also and can be used well after the information was gathered, as evidenced by the seven-year time lag in information analysis. There may be plenty more multi-body asteroid systems in the asteroid belt that make the orbital mechanics of even a four-body problem look like a piece of cake.
Originally published on Universe Today.