Porthan is a large asteroid orbiting between Mars and Jupiter in the main portion of the asteroid belt. NASA JPL has not classified Porthan as potentially hazardous because its orbit does not bring it close to Earth.
Porthan orbits the sun every 1,570 days (4.30 years), coming as close as 2.29 AU and reaching as far as 3.00 AU from the sun. Porthan is about 23.5 kilometers in diameter, making it larger than 99% of asteroids, comparable in size to the city of Indianapolis.
The rotation of Porthan has been observed. It completes a rotation on its axis every 27.78 hours.
Porthan's orbit is 1.34 AU from Earth's orbit at its closest point. This means that there is an extremely wide berth between this asteroid and Earth at all times.
Orbital simulations conducted by NASA JPL's CNEOS do not show any close approaches to Earth.
Porthan's orbit is determined by observations dating back to March 3, 1943. It was last officially observed on July 1, 2023. The IAU Minor Planet Center records 5,473 observations used to determine its orbit.
The position of Porthan is indicated by a ◯ pink circle. Note that the object may not be in your current field of view. Use the controls below to adjust position, location, and time.