‘Oumuamua is a comet, and an unusual one at that.
The first-known visitor from outside the Solar System, an object dubbed ‘Oumuamua, is an icy comet rather than a rocky asteroid. New measurements help to confirm early guesses as to the composition of the interstellar interloper, and could also aid researchers in their hunt for similar objects in our Solar System.
Careful observations of ‘Oumuamua’s orbit showed that as the object flew through space, something continually nudged it a tiny bit farther from the Sun than expected. That something was probably ice that warmed up and sprayed gas into space. This process is characteristic of a comet, rather than an asteroid, even though ‘Oumuamua never displayed the glorious tail of gas and dust that accompanies most comets.
(1I/2017 U1) は、2017年に発見された、天体観測史上初となる太陽系外から飛来した恒星間天体 (interstellar object) と目される天体。
October 26, 2017 04:52pm ET
A/2017 U1 made its closest approach to Earth on Oct. 14, coming within 15 million miles (24 million kilometers) of us — about 60 times the Earth-moon distance. The object is now above the ecliptic and rocketing toward the outer solar system at about 97,200 mph (156,400 km/h) relative to the sun, in the direction of the constellation Pegasus, researchers said.
The first-known visitor from outside the Solar System, an object dubbed ‘Oumuamua, is an icy comet rather than a rocky asteroid. New measurements help to confirm early guesses as to the composition of the interstellar interloper, and could also aid researchers in their hunt for similar objects in our Solar System.
Careful observations of ‘Oumuamua’s orbit showed that as the object flew through space, something continually nudged it a tiny bit farther from the Sun than expected. That something was probably ice that warmed up and sprayed gas into space. This process is characteristic of a comet, rather than an asteroid, even though ‘Oumuamua never displayed the glorious tail of gas and dust that accompanies most comets.
(1I/2017 U1) は、2017年に発見された、天体観測史上初となる太陽系外から飛来した恒星間天体 (interstellar object) と目される天体。
October 26, 2017 04:52pm ET
A/2017 U1 made its closest approach to Earth on Oct. 14, coming within 15 million miles (24 million kilometers) of us — about 60 times the Earth-moon distance. The object is now above the ecliptic and rocketing toward the outer solar system at about 97,200 mph (156,400 km/h) relative to the sun, in the direction of the constellation Pegasus, researchers said.
