View Full Version : Objects or asteroids between Mercury and the Sun

2006-Mar-30, 02:42 PM
Are there any known or (unknown) objects ,asteroids comets orbiting the Sun closer than Mercurys orbit aroud the sun? What is the object known that is closest to the Sun of all the planets in our solarsystem?Is it safe and possible to send astronauts to a Comet or an asteroid that is twice as close to the Sun than Mercury is at perihelion? I am very curious of how it will be to get twice as close to the Sun than Mercurys perihelion. Thanks.

2006-Mar-30, 02:49 PM
There are comets regularly observed that get much closer to the Sun than Mercury, however they spend most of their time much further away. Concerning it being safe... Many comets that get very close to the Sun crumble and fall apart. This would be very unsafe for astronauts on those comets.

2006-Mar-30, 02:50 PM
Some of the comets go inside Mercury's orbit at perihelion, but I am not aware of any object that stays inside Mercury's orbit all the time. I suppose there could be some small objects, but they would be difficult to detect from earth because of the glare of the sun.

2006-Mar-30, 02:51 PM
There are the Vulcanoid asteroids (http://en.wikipedia.org/wiki/Vulcanoid_asteroid), but it seems they are only theoretical currently (none have been observed).

There are also Mercury-crosser asteroids (http://en.wikipedia.org/wiki/Mercury-crosser_asteroid) that have been observed.

2006-Mar-30, 02:53 PM
List of Apollo minor planets by perihelion distance (http://www.cfa.harvard.edu/iau/lists/Apollosq.html)

As you can see, yet unnamed asteroid 2005 HC4 comes within 0.071 AU (10.65 million km) of the Sun.

2006-Mar-30, 05:51 PM
Good question; this is an area of active research. Theory suggests that there should be a population of asteroids in a stable zone well inside Mercury's orbit; as Swift wrote though, none have been discovered yet.