(music throughout)
On January 9, 2020, NASA’s Lucy Mission Team revealed that it would be visiting not seven asteroids as planned, but eight.
As it turns out, Eurybates, one of the Trojan asteroids along Lucy’s path,
has a small satellite or moonlet orbiting it.
Finding these tiny, new worlds before Lucy is launched in 2021 means that
the team can investigate their orbits and plan for more detailed follow-up observations during fly-bys.
Dr. Keith Noll and other Lucy science team members
have been using the Hubble Space Telescope to search for satellites and rings around Lucy’s targets.
This can be challenging
since the raw images are often filled with bumps, blobs and diffraction spikes.
The Lucy team didn’t see any evidence of a new satellite until November 2019.
After experimenting with the brightness and contrast on the Hubble images,
Dr. Noll saw a peculiar, faint spot near the much brighter Eurybates.
Dr. Mike Brown, another team member,
noticed the spot showed up in a slightly different position
on another set of Hubble images taken two days later
This change suggested that the spot was an orbiting satellite.
The team went back to Hubble and got 3 more chances to make observations of the possible new satellite.
On the first two tries, the little moonlet was nowhere to be found.
But on the third observation on January 3rd, 2020 they found the possible new satellite again
It was clearly visible next to Eurybates, which is over 6000 times brighter.
This huge difference in brightness suggests that the satellite is less than 1 kilometer in diameter,
very small compared to Eurybates at 64 kilometers.
With a few more Hubble observations
the team pinned down the new satellite's orbit
And they proposed a name
The International Astronomical Union approved
and from now on the little satellite will be known as "Queta" after Enriqueta Basilio
the first woman to light the Olympic cauldron
Evidence indicates that the Trojan Asteroid Eurybates
is the largest fragment from a massive asteroid collision that happened billions of years ago
It is possible that the new satellite, Queta, is a remnant of that catastrophic event.
Whether with Hubble or with the Lucy spacecraft’s flyby,
each observation enriches our understanding about the Trojan asteroids’ formation
and Eurybates’ relationship with its newly discovered companion.
The discovery of this new moonlet around the Trojan asteroid Eurybates
is just a preview of the incredible scientific knowledge
that will be captured by the Lucy mission as it explores this area of our Solar System.