Narrator: People have been hunting for sungrazing comets
for well over a hundred years, but up to 1979
we only knew of less than a dozen. As of 2020, we have seen
around 4,000 sungrazers. Why did the number increase?
The answer lies along the route most sungrazers follow.
In the late 1800s, Heinrich Kreutz observed that a few recent comets
comets traveling near the Sun appeared to follow the same orbit.
On this Kreutz sungrazer path, as we've come to call it, it takes
the comet several hundred years to complete one loop around the Sun.
While there are other orbits of sungrazers, Kreutz comets are the most common.
All of the comets in this orbit came from a single comet that fell apart
near the Sun thousands of years ago.
As the comet moved closer to the sun, the ice binding it together evaporated, breaking it into
smaller pieces that the Sun's gravity pulled apart.
Every time a comet comes around the Kreutz path, this can happen again, resulting
in a new generation of comets. It might sound
like this would clutter the solar system full of comets, but that is not the case.
Most of the new comets are small enough that they become completely vaporized as they approach
the Sun. There are more comets observed in the last few decades,
not because there are more in the solar system but because we have better ways
to see them when they are close to the Sun.
Spotting a sungrazer from the ground is almost impossible because of the blinding sunlight.
Now, spacecraft uniquely design to look at the Sun can
block the brightest sunlight, making the job a lot easier.
Since the joint ESA/NASA mission SOHO launched in 1995,
it has shown us thousands more comets than any tool before it.
With SOHO we can now see the smaller, fainter comets
close to the sun, just long enough to add them to our list of sungrazers
before they vaporize. The spacecraft's data is available online,
so now, anyone can discover a comet.
Roughly 95% of these comets have been found by amateur astronomers.
SOHO isn’t the only Sun-observing spacecraft to have surprised us
with beautiful images of comets. NASA’s Solar Dynamics Observatory
has spotted sungrazers, too, though less frequently than SOHO
Now that we can observe comets better than ever - who knows?
- maybe you will spot the next sungrazer.