This October, NASA will launch Lucy, the very first space probe to visit the trojan asteroid population. Trojans are known as “time capsules from the birth of our Solar System.” On the night of May 8 to 9, 2021, you, as a citizen astronomer, will have a unique opportunity to contribute to space exploration. The double trojan asteroid Patroclus and its companion Menoetius, one of Lucy’s targets, will occult (pass in front of) a bright star over the USA. By detecting this occultation, you can help NASA to improve Lucy’s guidance system.
Check out Patroclus’ orbit below. It’s the second largest trojan asteroid known made of two components of approximately 122 and 112 km across, and it will be the last stop made by the Lucy spacecraft during its unique journey, with a fly-by scheduled in 2033. Your data may help Lucy fly safely near Patroclus and Menoetius!!
Below are the paths of the occultation. Note that there are two paths: Not only is Patroclus a trojan asteroid, but it is also a double asteroid, with a companion called Menoetius that is only slightly smaller than its primary. Depending on where you live, you will have the opportunity to detect either Patroclus or Menoetius. Patroclus’ shadow will travel over the USA from California to Wisconsin, while Menoetius’ shadow will go from Texas to Ohio.
Figure 1.Path of Patroclus’ shadow
Figure 2. Path of Menoetius’ (Patroclus’ moon) shadow
Ready to observe?
Both observations will happen on the night of May 8th to May 9th at 08:34 UTC – 04h34 EDT – 03h34 CDT – 02h34 MDT – 01h34 PDT and will last for 04min00s.
The coordinates of the occulted star is:
RA : 16h 00m 08s
DEC : -28° 49′ 20”
Go to our asteroid occultations’ prediction webpage for more details on this event including accurate location, timing, and more.
Did you know? The companion of (617) Patroclus was named Menoetius, father of Patroclus.
The Unistellar team already successfully detected two of Lucy’s targets: Leucus and Orus. A citizen astronomer detecting an occultation of a bright star by a trojan asteroid would be a fantastic achievement, in line with Unistellar’s successes with the Lucy mission. We have already detected occultations by two asteroids to be visited by Lucy, Leucus and Orus.