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699 Hela

File:699Hela_(Lightcurve_Inversion).png · Wikimedia Commons · See Wikimedia Commons

EntityQ156599· pop 39· linked from 9 articles

Also known as (699) Hela, Hela

Mars-crossing 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
J. Helffrich
Discovery site
Heidelberg
Discovery date
5 June 1910
Pronunciation
/ ˈ h iː l ə /
Alternative designations
1902 WE · 1910 LC · 1923 TB · 1948 KD · 1957 WX 1
Minor planet category
Mars crosser
Observation arc
113.38 yr (41,411 d)
Aphelion
3.6831 AU (550.98 Gm )
Perihelion
1.5414 AU (230.59 Gm)
Semi major axis
2.6123 AU (390.79 Gm)
Orbital period sidereal
4.22 yr (1,542.1 d)
Mean anomaly
3.93957 °
Mean motion
0° 14 0.384 / day
Inclination
15.297°
Longitude of ascending node
242.548°
Argument of perihelion
91.479°
Earth moid
0.62609 AU (93.662 Gm)
Mars moid
0.4063 AU (60.78 Gm)

via Wikipedia infobox

Wikidata facts

Orbital period
1544.405486890374
Image
699Hela (Lightcurve Inversion).png
Show 14 more facts
provisional designation
A910 LC
time of discovery or invention
1910-06-05
orbital inclination
15.2864389423614
Commons category
699 Hela
rotation period
3.3962
absolute magnitude
11.44
orbital eccentricity
0.4096638114687348
semi-major axis of an orbit
2.6148208504479
periapsis
1.543623374545495
apoapsis
3.686018326350306
longitude of ascending node
242.4849685780062
argument of periapsis
91.55575973102606
mean anomaly
77.54416746546836
time of periapsis
2460667.8343396946
Sources (2)

via Wikidata · CC0

~3 min read

Article

699 Hela is a Mars crossing asteroid. It was discovered on 5 June 1910 at Heidelberg Observatory by German astronomer Joseph Helffrich, and may have been named after Hel, the Norse ruler of the underworld. This asteroid is orbiting the Sun at a distance of 2.61 astronomical units (AU) with a period of 4.22 years and an eccentricity of 0.41. The orbital plane is inclined at an angle of 15.3° to the plane of the ecliptic.

History and naming

Gallery (3)

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