سیارک ۹۱۸

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

(918) Itha

Orbit class

Main-belt

Semi-major axis

2.866 AU

Eccentricity

0.188

Inclination

12.067 °

Absolute magnitude

10.730 H

via Minor Planet Center

Key facts

Discovered by

K. Reinmuth

Discovery site

Heidelberg Obs.

Discovery date

22 August 1919

Named after

Name picked from the almanac , Lahrer Hinkender Bote

Alternative designations

A919 QD · 1919 FR, A907 CA · 1907 CA, 1943 PB

Minor planet category

main-belt · ( outer ) , Itha

Observation arc

99.72 yr (36,421 d)

Aphelion

3.4078 AU

Perihelion

2.3197 AU

Semi major axis

2.8637 AU

Orbital period sidereal

4.85 yr (1,770 d)

Mean anomaly

273.51 °

Mean motion

0° 12 12.24 / day

Inclination

12.070°

Longitude of ascending node

330.46°

Argument of perihelion

15.565°

Mean diameter

20.44 ± 1.9 km 21.37 ± 0.84 km 21.561 ± 0.106 km

Synodic rotation period

3.473 93 ± 0.000 06 h

via Wikipedia infobox

Wikidata facts

Instance of

asteroid

Followed by

919 Ilsebill

Follows

917 Lyka

Parent body

Sun

Minor-planet group

asteroid belt

Diameter

21.561

Orbital period

1772.437359618509

Image

000918-asteroid shape model (918) Itha.png

via Wikidata · CC0