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
- J. Palisa
- Discovery site
- Vienna
- Discovery date
- 16 August 1909
- Alternative designations
- 1909 HG
- Observation arc
- 97.38 yr (35569 d)
- Aphelion
- 3.4628 AU (518.03 Gm )
- Perihelion
- 1.9794 AU (296.11 Gm)
- Semi major axis
- 2.7211 AU (407.07 Gm)
- Orbital period sidereal
- 4.49 yr (1639.5 d )
- Mean anomaly
- 260.701 °
- Mean motion
- 0° 13 10.488 / day
- Inclination
- 14.878°
- Longitude of ascending node
- 334.346°
- Argument of perihelion
- 52.932°
- Mean diameter
- 22 ± 0.5 km
- Mass
- 1.9 × 10 kg (estimate)
- Synodic rotation period
- 7.40 h (0.308 d )
- Temperature
- unknown
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Followed by
- 688 Melanie
- Follows
- 686 Gersuind
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 21.533
- Orbital period
- 1641.97226965818
- Image
- Орбита астероида 687.png
Show 18 more facts
- discoverer or inventor
- Johann Palisa
- site of astronomical discovery
- Vienna Observatory
- provisional designation
- A909 QB
- time of discovery or invention
- 1909-08-16
- orbital inclination
- 14.8729265158234
- argument of periapsis
- 52.66633556702408
- albedo
- 0.079
- rotation period
- 7.3962
- asteroid spectral type
- X-type asteroid
- absolute magnitude
- 11.63
- orbital eccentricity
- 0.2713176729087328
- semi-major axis of an orbit
- 2.723819100165833
- periapsis
- 1.984798840484481
- apoapsis
- 3.462839359847185
- longitude of ascending node
- 334.293237092567
- mean anomaly
- 287.1580427582863
- time of periapsis
- 2461332.734649607
- epoch
- November 21, 2025
Sources (2)
via Wikidata · CC0
~1 min read
Encyclopedic overview
687 Tinette is a minor planet, specifically an asteroid orbiting primarily in the asteroid belt. It was discovered by Austrian astronomer Johann Palisa on 16 August 1909 from Vienna and was given the preliminary designation 1909 HG.
Photometric observations at the Palmer Divide Observatory in Colorado Springs, Colorado, in 1999 were used to build a light curve for this object. The asteroid displayed a rotation period of 7.40 ± 0.02 hours and a brightness variation of 0.25 ± 0.01 in magnitude.
Excerpted from Wikipedia’s “687 Tinette” article, available under the CC BY-SA 4.0 licence.