2021 ER is a very small asteroid whose orbit could bring it in close proximity to Earth. NASA JPL has classified 2021 ER as a "Near Earth Asteroid" due to its orbit's proximity to Earth, but it is not considered potentially hazardous because computer simulations have not indicated any imminent likelihood of future collision.
2021 ER orbits the sun every 304 days (0.83 years), coming as close as 0.75 AU and reaching as far as 1.02 AU from the sun. Based on its brightness and the way it reflects light, 2021 ER is probably between 0.007 to 0.031 kilometers in diameter, making it a small to average asteroid, very roughly comparable in size to a school bus or smaller.
2021 ER's orbit is 0.00 AU from Earth's orbit at its closest point. This means that its orbit is relatively close to Earth's orbit.
2021 ER has 6 close approaches predicted in the coming decades:
| Date | Distance from Earth (km) | Velocity (km/s) |
|---|---|---|
| March 3, 2021 | 684,736 | 4.246 |
| March 6, 2026 | 2,405,931 | 3.963 |
| Dec. 19, 2030 | 29,463,497 | 3.611 |
| April 29, 2031 | 16,357,884 | 5.414 |
| Feb. 28, 2050 | 2,124,227 | 4.560 |
| June 29, 2050 | 24,930,341 | 3.134 |
NASA Sentry has assessed impact risk for 29 very close approach scenarios. Here are the top scenarios ordered by probability of impact:
| Date | Probability of Impact (%) | Impact Energy (Mt) |
|---|---|---|
| March 1, 2110 | 0.00231 | 0.05654 |
| March 1, 2110 | 0.00220 | 0.0565 |
| Feb. 28, 2098 | 0.00180 | 0.05652 |
| Feb. 28, 2084 | 0.00026 | 0.05651 |
| Feb. 29, 2080 | 0.00014 | 0.05636 |
| March 1, 2105 | 0.00009 | 0.05646 |
| March 1, 2115 | 0.00008 | 0.05655 |
| Feb. 29, 2076 | 0.00006 | 0.05655 |
| Feb. 28, 2088 | 0.00006 | 0.05657 |
| March 1, 2113 | 0.00005 | 0.05662 |
| March 1, 2115 | 0.00003 | 0.05655 |
| March 1, 2112 | 0.00001 | 0.05652 |
| Feb. 28, 2091 | 0.00001 | 0.05734 |
| Feb. 29, 2120 | 0.00001 | 0.05659 |
| March 1, 2122 | 0.00001 | 0.05655 |
| Feb. 28, 2072 | 0.00000 | 0.05645 |
| Feb. 28, 2085 | 0.00000 | 0.05664 |
| Feb. 27, 2098 | 0.00000 | 0.0565 |
| March 1, 2105 | 0.00000 | 0.05646 |
| Feb. 27, 2089 | 0.00000 | 0.05647 |
| Feb. 28, 2106 | 0.00000 | 0.0565 |
| March 1, 2103 | 0.00000 | 0.05645 |
| Feb. 28, 2082 | 0.00000 | 0.05665 |
| Feb. 29, 2088 | 0.00000 | 0.05633 |
| Feb. 27, 2097 | 0.00000 | 0.05648 |
| March 1, 2115 | 0.00000 | 0.05644 |
| Feb. 28, 2108 | 0.00000 | 0.05673 |
| Feb. 29, 2084 | 0.00000 | 0.05631 |
| Feb. 29, 2080 | 0.00000 | 0.0565 |
2021 ER's orbit is determined by observations dating back to March 5, 2021. It was last officially observed on April 8, 2021. The IAU Minor Planet Center records 81 observations used to determine its orbit.
2021 ER can be reached with a journey of 370 days. This trajectory would require a delta-v of 6.415 km/s. To put this into perspective, the delta-v to launch a rocket to Low-Earth Orbit is 9.7 km/s. There are 199,621 potential trajectories and launch windows to this asteroid.
See more at the NHATS Mission Trajectories table for 2021 ER.
The position of 2021 ER 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.