225 Henrietta
Also known as (225) Henrietta, Henrietta
outer main-belt asteroid
Picture of the Day · NASA
Jupiter and Venus from Earth
2026-06-07
It was visible around the world. The sunset conjunction of Jupiter (left) and Venus (right) in 2012 was visible almost no matter where you lived on Earth. Anyone on our planet with a clear western horizon at sunset could see them. That year, a creative photographer traveled away from the town lights of Szubin, Poland to photograph a near closest approach of the two planets. The bright planets were then separated by only three degrees and his daughter struck a humorous pose. A faint red sunset still glowed in the background. Jupiter and Venus are together again this week after sunset, passing within a degree of each other about two days from today.
© Marek Nikodem (PPSAE) · via NASA APOD
Key facts
- Discovered by
- Johann Palisa
- Discovery date
- 19 April 1882
- Pronunciation
- / h ɛ n r i ˈ ɛ t ə /
- Named after
- Henrietta Jansen
- Alternative designations
- A882 HA
- Minor planet category
- Main belt ( Cybele )
~2 min read
Article
225 Henrietta is a very large outer main-belt asteroid. It was discovered by Austrian astronomer Johann Palisa on April 19, 1882, in Vienna and named after Henrietta, wife of astronomer Pierre J. C. Janssen. The asteroid is orbiting at a distance of 3.39 AU from the Sun with a period of 6.24 years and an eccentricity (ovalness) of 0.26. The orbital plane is inclined at an angle of 20.9° to the plane of the ecliptic. 225 Henrietta belongs to Cybele group of asteroids.
This is classified as a C-type asteroid and is probably composed of primitive carbonaceous material. It has a very dark surface, with an albedo of 0.040. Photometric measurements made from the Oakley Southern Sky Observatory during 2012 gave a light curve with a period of 7.352±0.003 h and a variation in brightness of 0.18±0.02 in magnitude. This is consistent with a synodic rotation period of 7.356±0.001 h determined in 2000. In 2001, the asteroid was detected by radar from the Arecibo Observatory at a distance of 1.58 AU. The resulting data yielded an effective diameter of 128±16 km.