Picture of the Day · NASA
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
- WISE spacecraft
- Discovery site
- LEO , polar orbit
- Discovery date
- 1 October 2010
- Minor planet category
- Earth trojan Aten (2014) Apollo (2013)
- Observation arc
- 768 days (2.10 yr)
- Aphelion
- 1.1903 AU (178.07 Gm )
- Perihelion
- 0.80918 AU (121.052 Gm)
- Semi major axis
- 0.99972 AU (149.556 Gm)
- Orbital period sidereal
- 1.00 yr (365.10 d )
- Average orbital speed
- 29.8 km/s
- Mean anomaly
- 354.14 °
- Mean motion
- 0° 59 9.672 / day
- Inclination
- 20.890°
- Longitude of ascending node
- 96.498°
- Argument of perihelion
- 45.927°
- Earth moid
- 0.0837911 AU (12.53497 Gm)
- Mean diameter
- 379 ± 123 m
- Geometric albedo
- 0.059 ± 0.049
via Wikipedia infobox
Wikidata facts
- Instance of
- near-Earth object
- Parent body
- Sun
- Minor-planet group
- Earth trojan
- Diameter
- 0.379
- Orbital period
- 364.4742660097215
- Image
- PIA14405-full crop.jpg
Show 17 more facts
- time of discovery or invention
- 2010-10-01
- orbital eccentricity
- 0.1903335837988096
- mean anomaly
- 306.8679340196849
- argument of periapsis
- 46.06075001931062
- longitude of ascending node
- 96.41542146013188
- Commons category
- 2010 TK7
- absolute magnitude
- 20.78
- albedo
- 0.059
- provisional designation
- 2010 TK7
- semi-major axis of an orbit
- 0.9985710293634634
- periapsis
- 0.8085094266670491
- apoapsis
- 1.188632632059878
- time of periapsis
- 2461054.2924187495
- epoch
- November 21, 2025
- orbital inclination
- 20.90535521758466
- discoverer or inventor
- Wide-field Infrared Survey Explorer
- site of astronomical discovery
- Wise Observatory
Sources (2)
via Wikidata · CC0
~6 min read
Encyclopedic overview
(706765) 2010 TK7 is a sub-kilometer near-Earth asteroid and the first Earth trojan discovered; it precedes Earth in its orbit around the Sun. Trojan objects are most easily conceived as orbiting at a Lagrangian point, a dynamically stable location (where the combined gravitational force acts through the Sun's and Earth's barycenter) 60 degrees ahead of or behind a massive orbiting body, in a type of 1:1 orbital resonance. In reality, they oscillate around such a point. Such objects had previously been observed in the orbits of Mars, Jupiter, Neptune, and the Saturnian moons Tethys and Dione.
2010 TK7 has a diameter of about 300 meters (1,000 ft). Its path oscillates about the Sun–Earth L4 Lagrangian point (60 degrees ahead of Earth), shuttling between its closest approach to Earth and its closest approach to the L3 point (180 degrees from Earth).
Excerpted from Wikipedia’s “(706765) 2010 TK7” article, available under the CC BY-SA 4.0 licence.