C/1861 G1 (Thatcher) is a large comet whose orbit does not match any defined comet orbit class. NASA JPL has not classified Thatcher as potentially hazardous because its orbit does not bring it close to Earth.
Thatcher orbits the sun every 152,000 days (416.15 years), coming as close as 0.92 AU and reaching as far as 110.44 AU from the sun. Its orbit is highly elliptical. Based on its brightness and the way it reflects light, Thatcher is probably between 2658.000 to 5943.469 kilometers in diameter, making it the largest asteroid/dwarf planet, very roughly comparable in size to the U.S. state of Alaska.
Thatcher's orbit is 0.00 AU from Earth's orbit at its closest point. This means that its orbit is very close to Earth's orbit.
Orbital simulations conducted by NASA JPL's CNEOS do not show any close approaches to Earth.
Thatcher's orbit is determined by observations dating back to April 11, 1861. It was last officially observed on Sept. 7, 1861. The IAU Minor Planet Center records 187 observations used to determine its orbit.
The position of C/1861 G1 (Thatcher) 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.