The Minor Planets Observers Switzerland (MPOS) is a working group of the Swiss Astronomical Society. The members are engaged in the precise determination of the position and of the photometry of Minor Bodies, such as Asteroids, Comets and Dwarf Planets. The knowledge of these data allows to adjust continously the orbital elements of these bodies and inform about their rotational aspects.

Join our group! New observers are welcome at any time!

Please visit also our forum "SAG Fachgruppe Kleinplaneten".

Latest activities

Mid of event
Asteroid Type / Class
Station Information
18:14:00 UT -
19:36:00 UT
(1685) Toro
Apollo (NEO) SIM
Robert Glaisen
Report (Robert Glaisen)
Orbital Elements


Sept. 11, 2023:   Robert Glaisen (Observatory Simplonadler SIM) recorded the Apollo type asteroid (458732) 2011 MD5 shortly before his brightest light (Sept. 17: 13.9 mag) and his closest passage (Sept. 22: 11.374 mio km). The asteroid measures about 900 m in diameter.
Based on the recordings, Remo Glaisen created a summary about this event.
Aug. 03, 2023:   Robert Glaisen (Observatory Simplonadler SIM) recorded the Amor type asteroid (154244) 2002 KL6 only two days before its closest distance to Earth. The asteroid measures about 1 km in diameter. The path of it was defined with totally 17 images.
Based on the recordings, Remo Glaisen created a summary about this event.
Jan. 14, 2023:   Agenda: "Call for Observation" actualized for February 2023. Clear skies!
Feb. 27/28 and
Mar. 03, 2022:
  Robert Glaisen (Observatories Simplonadler SIM and Rhonesand BRI) recorded the Amor type asteroid (153591) 2001 SN263 during its close passage. After measuring the brightness of the asteroid during three nights, Robert was able to confirm the rotational period of the 2km-asteroid. Congratulations!
Jan. 19, 2022:   Robert Glaisen (Observatory Rhonesand BRI) recorded the Apollo type asteroid (7482) 1994 PC1 only a few hours after its closest distance to Earth. The 1.1 km asteroid crossed the sky rapidly with 80 arcsec/minute.
July 18, 2021:   Robert Glaisen (Observatory Simplon Adler SIM) recorded the Amor type asteroid (285571) 2000 PQ9 near Earth. This asteroid remains between the orbits of Earth and Mars, that's why it is not classified as a Potentially Hazardous Asteroid (PHA).
After the analyze of the pictures, a further asteroid was detected in the field of view: (7505) Furusho 1997 AM2 is crossing the orbit of Mars and not hazardous for Earth.
Mar. 01, 2021:   Robert Glaisen (Observatory Simplon Adler SIM) recorded the Apollo type asteroid 1999 RM45 just hours before its closest approach to the Earth. This asteroid is classified as a Potentially Hazardous Asteroid (PHA)
Sept. 17/18 and
Oct. 18/19, 2020:
  During two nights, Robert Glaisen (Observatory Simplon Adler) observed and recorded the Amor type asteroid (159402) 1999 AP10. The analyze of the lightcurve shows clearly the period of rotation.
Sept. 26, 2020:   Raoul Behrend et al. recorded the lightcurve of the slightly peanut-shaped asteroid (885) Ulrike. It appears that the multi-chords occultation of 2020-07-12 occured near 30 minutes of time after a maximum of brightness. It is in good agreement with to what one can conclude from the silhouette on Eric Frappa's website (Euraster). The apparent period of rotation is 0.204453±0.000010 day.
Apr. 11-15, 2020:   A few nights before it's closest approach to Earth, Robert Glaisen (Observatory Simplon Adler) captured the Amor type asteroid (52768) 1998 OR2. Beside of localisation and imaging the Near Earth Object (NEO), some measurements of its brightness were taken too.
Feb. 14, 2020:   One night before it's closest approach, Remo Glaisen and Thomas Lüthi (Observatory Simplon Adler) captured the Apollo type asteroid (163373) 2002 PZ39, just passing the Plejades. After checking the image, some other moving objects were discovered...
Mar. 10, 2019:   During four nights between Dec. 28, 2018 and Feb. 5, 2019, Stefano Sposetti recorded the brightness of the Asteroid (686) Gersuind. These clear data allowed to determine the rotation period of this object with high accuracy.
Sept. 09, 2018:   Early morning of September 9, Thomas Lüthi captured the asteroid 2018 RC, which was discovered only a few days before. The pictures were taken with a refractor Borg ED 101 (f = 640mm x 0.8) and a Canon EOS20Da (exposure time 300 sec. at ISO 1600). At that time, 2018 RC (a near-Earth object of the Aten group) was crossing the constellation of Aquarius.
Jan. 01, 2018:   Just to the beginning of the new year, a near-Earth asteroid crossed the Earth's orbit: (2017 YD) with an estimated diameter of 22-50 m passed the Earth in a distance of 19 LD (lunar distances).
Coming near passages of asteroids can be found here.
Oct. 18, 2017:   The new discovered asteroid 1I/2017 U1 "Oumuamua" seems to be an interstellar visitor: Coming from direction Vega, it entered the solar system with a velocity of about 40 km/s on a hyperbolic orbit with high inclination. The asteroid passed the earth, still un-discovered, on October 14, 2017. On September 9, 2017, it passed the sun in a distance of only 37.6 million kilometers, a fourth of the distance Earth-Sun. The strange shaped, 400 m long object is ten times as long as wide and rotates quite fast. Mid of 2018, it will pass the orbit of Jupiter and beginning 2019 the one of Saturn. Further destination: Constellation Pegasus.
Orbital Elements  More 1...  2...
Oct. 14, 2017:   "3 - 2 - 1 - lift off" for the new working group! Let's watch asteroids!