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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
- P. M. Henry
- Discovery date
- 4 November 1875
- Pronunciation
- / ˈ b ɜːr θ ə /
- Alternative designations
- A875 VD
- Minor planet category
- Main belt
- Observation arc
- 130.75 yr (47758 d)
- Aphelion
- 3.44 AU (515.21 Gm )
- Perihelion
- 2.95 AU (441.30 Gm)
- Semi major axis
- 3.20 AU (478.26 Gm)
- Orbital period sidereal
- 5.72 years (2,087.9 d)
- Average orbital speed
- 16.63 km/s
- Mean anomaly
- 125.046°
- Mean motion
- 0° 10 20.734 / day
- Inclination
- 20.9724°
- Longitude of ascending node
- 36.7441°
- Argument of perihelion
- 159.722°
- Earth moid
- 1.95 AU (291.94 Gm)
- Jupiter moid
- 1.53 AU (229.03 Gm)
via Wikipedia infobox
~2 min read
Encyclopedic overview
154 Bertha is a main-belt asteroid. It was discovered by the French brothers Paul Henry and Prosper Henry on 4 November 1875, but the credit for the discovery was given to Prosper. It is probably named after Berthe Martin-Flammarion, sister of the astronomer Camille Flammarion.
Observations performed at the Palmer Divide Observatory in Colorado Springs, Colorado in during 2007 produced a light curve with a period of 22.30 ± 0.03 hours and a brightness range of 0.10 ± 0.02 in magnitude. A 1998 measurement gave a value of 27.6 hours, which doesn't fit the PDO data. In 2011, observations from the Organ Mesa Observatory in Las Cruces, New Mexico were used to determine a rotation period of 25.224 ± 0.002 hours with a brightness variability of 0.10 ± 0.01 magnitude, ruling out previous studies.
Excerpted from Wikipedia’s “154 Bertha” article, available under the CC BY-SA 4.0 licence.