Interstellar Interloper 3I/ATLAS from Hubble
Discovered on July 1
with the NASA-funded ATLAS
(Asteroid Terrestrial-impact Last Alert
System) survey telescope in Rio Hurtado, Chile,
3I/ATLAS is so designated as the third known interstellar object
to pass through our Solar System.
It follows
1I/ʻOumuamua in 2017 and the comet
2I/Borisov in 2019.
Also known as
C/2025 N1, 3I/ATLAS is a comet.
A teardrop-shaped cloud of dust, ejected from its icy nucleus
warmed by increasing sunlight, is seen in this
sharp image from the Hubble
Space Telescope captured on July 21.
Background stars are streaked in the exposure as Hubble tracked
the fastest comet
ever recorded on its journey toward the inner solar system.
An analysis
of the Hubble image indicates the
solid nucleus, hidden
from direct view, is likely less that 5.6 kilometers in diameter.
This comet's interstellar origin is
clear from its orbit,
determined to be an eccentric, highly hyperbolic orbit that does
not loop back around the Sun and will return
3I/ATLAS
to interstellar space.
Not a threat to
planet Earth,
the inbound interstellar interloper is now
within the Jupiter's orbital distance of the Sun, while its
closest approach to the Sun will bring it just inside the orbital
distance of Mars.