(66063) 1998 RO1
A stony Aten binary with a close-orbiting moon.
(66063) 1998 RO1 is a stony asteroid from the Aten group, a class of near-Earth objects. It follows a highly eccentric orbit and forms a synchronous binary system roughly 800 meters across. The asteroid was discovered on 14 September 1998 by researchers with the Lincoln Near-Earth Asteroid Research program at the Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico. As of 2017, it was one of only seven known binary systems within the Aten group.
Its orbit is extremely elongated, taking it from inside Mercury's orbit at its closest point to the Sun out beyond Mars at its farthest. The asteroid completes one orbit around the Sun every 360.29 days, or about 0.99 years. While it does make close approaches to Earth, it comes even closer to other inner planets, especially Mars. The closest recorded approach to any planet between 1950 and 2200 occurred on 18 March 1964, when it passed within 0.00898 AU (about 1,343,000 kilometers) of Mars. It will make an even closer pass to Mars on 12 October 2065, coming within 0.0054 AU (about 810,000 kilometers).
The asteroid has one unnamed moon, discovered through lightcurve observations between 13 and 28 September 2013, with confirmation from radar observations at the Arecibo Observatory a year later. The satellite orbits extremely close to its primary, with a semi-major axis of just 800 meters (about 2,600 feet) and an orbital eccentricity of 0.06. This gives it a periapsis of 752 meters (2,467 feet) and an apoapsis of 848 meters (2,782 feet). It completes one orbit every 14.54 hours. The moon is about 48% the size of the primary, measuring roughly 380 meters across.
The Minor Planet Center assigned the asteroid its permanent number on 10 September 2003. As of 2018, it had not received a name.
Quick Facts
- Minorplanet
- yes
- Background
- #FFC2E0
- Discoverer
- LINEAR
- Discovery Site
- Lincoln Lab's ETS
- Discovered
- 14 September 1998
- Mpc Name
- (66063) 1998 RO · 1
- Mp Category
- NEOAten
- Epoch
- 4 September 2017 (JD 2458000.5)
- Uncertainty
- 0
- Observation Arc
- 13.99 yr (5,111 days)
- Aphelion
- 1.7045 AU
- Perihelion
- 0.2774 AU
Facts from the source article.
Lore & Background
The asteroid was discovered on 14 September 1998 by the Lincoln Near-Earth Asteroid Research team at the Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico. It belongs to the Aten group, a class of near-Earth objects with orbits that cross Earth's. Its orbit is highly eccentric, with an aphelion beyond Mars and a perihelion inside Mercury's orbit, and it has an orbital period of 360.29 days (0.99 years).
1998 RO1 makes close approaches to Earth, but its closest approaches are to Mars. Between 1950 and 2200, its nearest planetary approach was to Mars on 18 March 1964, passing at 0.00898 AU (1,343,000 km), and it will pass even closer to Mars on 12 October 2065 at 0.0054 AU (810,000 km).
The asteroid has one unnamed natural satellite, discovered from lightcurve observations between 13 and 28 September 2003 and confirmed by radar observations from the Arecibo Observatory one year later. The moon measures approximately 48% of the primary's diameter, or about 380 meters. It orbits at a semi-major axis of 800 m with an eccentricity of 0.06, giving a periapsis of 752 m and an apoapsis of 848 m, completing one orbit every 14.54 hours. The primary itself has an orbital period of 14.53 hours, indicating a synchronous system.
Reader's Guide
As one of only seven known Aten binaries as of 2017, (66063) 1998 RO1 holds significance in the study of binary asteroid systems among near-Earth objects. Its highly eccentric orbit, which takes it from inside Mercury's orbit to beyond Mars, makes it a dynamic object for understanding orbital evolution and planetary interactions. The close approaches to Mars, particularly the 1964 and 2065 encounters, provide opportunities for studying gravitational perturbations. The discovery of its moon in 2003 through lightcurve and radar observations added to the growing catalog of asteroid satellites, and the synchronous nature of the system—where the primary's rotation and the moon's orbital period are nearly identical—offers insights into tidal locking and binary formation mechanisms. The asteroid was numbered by the Minor Planet Center on 10 September 2003 but, as of 2018, had not been named.
Did You Know?
- The asteroid's moon measures about 380 meters, roughly 48% of the primary's diameter.
- Its closest approach to a planet between 1950 and 2200 was to Mars on 18 March 1964.
- The moon was discovered from lightcurve observations in September 2003 and confirmed by Arecibo radar a year later.
Frequently Asked Questions
What is (66063) 1998 RO1?
It is a stony near-Earth asteroid belonging to the Aten group, best known for being a synchronous binary system in which a smaller companion orbits the primary body.
How large is (66063) 1998 RO1?
The primary asteroid measures roughly 800 meters in diameter, while its moon is approximately 380 meters across.
What is special about (66063) 1998 RO1's orbit?
Its path is extremely elongated, swinging from inside Mercury's orbit at perihelion all the way out past Mars at aphelion, completing one loop in about 360 days.
Who discovered (66063) 1998 RO1 and where?
The asteroid was spotted on 14 September 1998 by the Lincoln Near-Earth Asteroid Research team operating from the Lincoln Laboratory Experimental Test Site near Socorro, New Mexico.
Why is (66063) 1998 RO1 considered rare?
As of 2017 it stood as one of only seven confirmed binary systems within the entire Aten group, making paired near-Earth objects like it a genuinely uncommon find.
More in Notable Asteroids, Part 4 1-24
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