Orange Dwarf Star Set to Smash into The Solar System

[bdewoody]

I have a feeling this will be the topic of an upcoming Science Channel/History Channel/Discovery Channel broadcast that will emphasize the castistrophic effects of said event and will barely mention it is 1.5 million years away.

 

[ZenGalacticore]

So this may happen in 1.5 million years, but its never happened in the entire 4.5 billion year history of the Sun?

The Sun has gone around the Galaxy what, 20 or so times in its history, with all that "popcorn popping" movement of all the other stars, and this has never happened before? I wonder, what are the odds?

 

[EarthlingX]

Wiki has a wonderful article about Oort cloud
Lots of images too ..

An Atlas of The Universe is also worth checking.

This article from Astrobiology Magazine is also related, i think :

Getting WISE About Nemesis

Posted: 03/11/10
Author: Leslie Mullen
Summary: Is our Sun part of a binary star system? An unseen companion star, nicknamed “Nemesis,” may be sending comets towards Earth. If Nemesis exists, NASA’s new WISE telescope should be able to spot it.

Astronomers think there could be as many brown dwarfs as stars like our Sun, but brown dwarfs are often too cool to find using visible light. Using infrared light, the WISE mission could find many brown dwarfs within 25 light years of the Sun. These two pictures show simulated data before and after the WISE mission (stars are not real). The simulated picture on the left shows known stars (white and yellow) and brown dwarfs (red) in our solar neighborhood. The picture on the right shows additional brown dwarfs WISE is expected to find.
Image credit: NASA/JPL-Caltech

I think there is a lot of undetected brown dwarfs, and even more smaller objects roaming the galaxy. Percentage of total baryonic matter held in stars, comparing to assumed percentage of gas and dust leads me to that conclusion.

Local densities would probably vary, depending on the local circumstances, such as being in a star cluster, or different distances from the galaxy center.

Chances to get closer to Sun than 1 pc would be probably higher, than those calculated above for the visible stars, if there are more of them, but gravitational effects would also be smaller.

Keeping an eye on the WISE Mission Thread; Launched Dec 14 (SDC) sounds wise

 

[EarthlingX]

More about it from NewScientist :

Hurtling star on a path to clip solar system

16:42 15 March 2010 by Rachel Courtland

A star is hurtling towards us. It will almost certainly clip the outskirts of the solar system and send comets towards Earth – though not for a while.

Bobylev's calculations suggest Gliese 710 has an 86 per cent chance of passing through the Oort cloud. This could scatter millions of comets into paths that cross Earth's orbit. Fortunately, previous work on the effect of a star tangling with the Oort cloud hints the comets would arrive in a trickle, with only one entering an Earth-crossing orbit per year.

Gliese 710 also has a 1 in 10,000 probability of coming within 1000 astronomical units – 1 AU being the distance from the Earth to the sun. Such a path could jostle objects in the Oort cloud, the Kuiper belt – a swarm of icy objects beyond Neptune's orbit – as well as others that orbit in a disc between the two regions. The star could also change Neptune's orbit a fraction, says Paul Weissman of NASA's Jet Propulsion Laboratory in Pasadena, California. "It would be a very significant event."

Journal reference: Astronomy Letters, vol 36, p 230

 

[CalliArcale]

So this may happen in 1.5 million years, but its never happened in the entire 4.5 billion year history of the Sun?

"Yes" and "nobody knows", respectively. The best we can say is that in the past 4.5 billion years, if it has happened, it has managed to do so without seriously disrupting the orbits of the major planets. There's not much past that which can be said. It could certainly have happened in that time; we just don't have any evidence pointing to a specific incident in the past.

 

[EarthlingX]

Some wild assumptions:
- asteroid hits the planet with simple life,
- some parts go back in space, with travellers,
- after a couple of million years another red dwarf comes by, with a Jupiter like planet, much closer to it than 1 AU, not too close though, and with some moons, melted by twist and shake, or maybe heated enough by the dwarf.
- our very lucky rock with the bug hits the moon, and voila, lively soup.

It's probably not so contagious, but i think, possible.