It is as inevitable as the Sun rising and the tides shifting. Another big
space object will one day strike the planet. For billions of years past and
billions of years to come, it has occurred and will continue to occur.
So far, humanity has been fortunate because we haven't had to deal with
such a terrible threat. But if we want to live on this planet for a long
time, we must accept that there will be dangerous asteroids and learn to
prepare for them.
The skies are still being watched over by organizations all around the
world. They are cataloging and mapping all NEOs, or near-Earth objects, that
could be dangerous. Thankfully, there are fewer of the larger rocks, which
obviously offer a greater concern. The majority of the potentially dangerous
asteroids bigger than one kilometer (0.6 miles) in diameter have credible
maps, despite the fact that our census of dangerous
NEOs
is far from comprehensive.
This is helpful, to put it mildly, because kilometer-scale asteroids have
the ability to not only destroy entire towns but also to hurt the
environment significantly all around the world.
A group of astronomers has
calculated the orbits of these massive NEOs over the next millennium in order to determine the
risk that they represent. According to their study, none of these
kilometer-scale NEOs represent a serious threat to mankind in the next
century.
Beyond that, though, it is challenging for us to forecast these NEOs'
orbits. This is due to the fact that
modest changes in orbital dynamics may have significant consequences over very long timeframes. An asteroid might be sent on a course that ends
up crossing the Earth in a few thousand years by a little variation in the
amount of energy it receives from the Sun or an unexpected tug from
Jupiter.
The researchers looked at the most direct collision between known dangerous
NEOs and the Earth. They focused on how this closest distance alters over
the duration of thousands and centuries. In order to accomplish this, they
ran a number of simulations that sketched out as many potential orbital
pathways as they could, taking into account the uncertainty in the NEOs'
present orbital locations and velocities.
One NEO in particular, Asteroid 7482, was singled out by scientists as
being particularly dangerous. For the next millennium, this asteroid will
spend a large amount of time close to the Earth. Even if it doesn't
guarantee that it will hit Earth, it does indicate that this rock has the
greatest likelihood of colliding with it within the next thousand
years.
Another asteroid that was highlighted by the researchers is Asteroid
143651, whose orbit is so erratic that it is hard to forecast its precise
location for more than a few decades. Therefore, given on our current
understanding of its position and its velocity, we are unable to declare
with certainty if it poses any threat at all.
28 candidates have a non-zero probability of a "deep encounter," which
implies they will pass
closer to the Moon than any other object, according to the researchers.
None of these things may collide with Earth in the next one hundred or a
thousand years, but if we're going to last the long haul, we need to be
aware of them.
This article was originally published by
Universe Today. Read the
original article.
