2021 XS4

Key Facts

• Categorized as a Aten-class Asteroid
• Comparable in size to a school bus or smaller
• Will pass within 8,196,517 km of Earth in 2019
• Classified as a Near Earth Asteroid (NEA)
• Not a Potentially Hazardous Object
• See orbit simulation

Overview

2021 XS4 is a very small asteroid whose orbit could bring it in close proximity to Earth. NASA JPL has classified 2021 XS4 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 XS4 orbits the sun every 364 days (1.00 years), coming as close as 0.81 AU and reaching as far as 1.19 AU from the sun. Based on its brightness and the way it reflects light, 2021 XS4 is probably between 0.017 to 0.038 kilometers in diameter, making it a small to average asteroid, very roughly comparable in size to a school bus or smaller.

Close Approaches

2021 XS4's orbit is 0.03 AU from Earth's orbit at its closest point. This means that there is a wide berth between this asteroid and Earth at all times.

2021 XS4 has 8 close approaches predicted in the coming decades:

Images and Observations

2021 XS4's orbit is determined by observations dating back to Dec. 8, 2021. It was last officially observed on Dec. 12, 2021. The IAU Minor Planet Center records 24 observations used to determine its orbit.

Accessibility and Exploration

This asteroid is not considered a viable target for human exploration by the NHATS study.

Similar Objects

These objects have orbits that share similar characteristics to the orbit of 2021 XS4:

• 3362 Khufu (1984 QA)
• 3753 Cruithne (1986 TO)
• 10563 Izhdubar (1993 WD)

References

• JPL Small Body Database
• Mission Design
• Sky Finder Chart

Orbit Simulation

Sky Map

The position of 2021 XS4 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.