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878 Mildred

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Also known as (878) Mildred, Mildred

main-belt asteroid

Picture of the Day · NASA

Pathfinder on Mars

Pathfinder on Mars

2026-07-04

On July 4th, 1997, using its own array of fireworks, a parachute, and a cocoon of airbags, the Mars Pathfinder spacecraft bounced like a giant beach ball at least 15 times before it came to rest on the surface of Mars at 10:07 AM Pacific Daylight Time. After its then novel airbag-assisted landing sequence was completed, Pathfinder transmitted this color mosaic to mission operators on Earth. In the scene from another world, the Mars Sojourner robot rover is visible in the foreground, crouched on top of the unfolded Pathfinder. About the size of a large house cat, the six-wheeled, solar-powered Sojourner became the first successful Martian rover. Surrounding Pathfinder are deflated airbags and the rock-strewn terrain of the Ares Vallis floodplain. In the distance Martian hills appear against a dusty brownish sky. The Pathfinder lander was subsequently renamed the Carl Sagan Memorial Station.

via NASA APOD

Key facts

Discovered by
S. B. Nicholson , H. Shapley
Discovery site
Mount Wilson Obs.
Discovery date
6 September 1916
Named after
Mildred Shapley Matthews
Alternative designations
1916 f, 1985 VG 6 , 1991 GZ 8
Minor planet category
main-belt Nysa
Observation arc
99.57 yr (36368 days)
Aphelion
2.8953 AU (433.13 Gm )
Perihelion
1.8286 AU (273.55 Gm)
Semi major axis
2.3619 AU (353.34 Gm)
Orbital period sidereal
3.63 yr (1325.9 d )
Mean anomaly
198.89 °
Mean motion
0° 16 17.472 / day
Inclination
2.0648°
Longitude of ascending node
172.83°
Argument of perihelion
190.14°
Dimensions
~4 km
Synodic rotation period
2.660 h (0.1108 d )

via Wikipedia infobox

Wikidata facts

Instance of
asteroid
Followed by
Q157589
Parent body
Sun
Minor-planet group
asteroid belt
Diameter
2.529
Orbital period
1325.089242251696
Show 17 more facts
discoverer or inventor
Harlow Shapley
site of astronomical discovery
Mount Wilson Observatory
provisional designation
A916 RC
time of discovery or invention
1916-09-06
orbital inclination
2.066612489118851
albedo
0.399
rotation period
2.6607
absolute magnitude
14.89
orbital eccentricity
0.2259789310322301
semi-major axis of an orbit
2.361009860496028
periapsis
1.827471376064581
apoapsis
2.894548344927476
longitude of ascending node
172.7980228458636
argument of periapsis
190.2457775699816
mean anomaly
42.6651873477965
time of periapsis
2460843.4578311853
Sources (2)

via Wikidata · CC0

~2 min read

Encyclopedic overview

878 Mildred is a minor planet in the main belt orbiting the Sun. It is the lowest numbered, and thus the namesake, of the Mildred family of asteroids, a subgroup of the Nysa family. The Mildred subgroup, and by extension 878 Mildred itself, is thought to have been formed by a recent fragmentation event from a larger asteroid.

Discovery

Excerpted from Wikipedia’s “878 Mildred” article, available under the CC BY-SA 4.0 licence.