It may seem that we have advanced far in the study of solar system comets, but in fact we have only slightly touched their mysteries. The image shows a shallow trail from the collision of comet Tempel 1 with the probe of the NASA mission Deep Impact. The telescope James Webb is able to “dive” into the study of comets a little deeper.
When the NASA telescope named after James Webb is released in 2018, cometary hunters will go all the way to work with it. That's because 6, 5-meter lens will give unprecedented clarity of images of comets flying near the Earth.
The new study, led by Michael S. P. Kelly, in collaboration with researchers at the University of Maryland, talks about the reasons why the James Webb telescope will be an excellent tool for studying comets. (This document will be published in publications of the Pacific Astronomical Society). Comets observers will compete with astronomers in all areas of research, such as observation of galaxies and the study of the origin of the universe.
Our problem is that comets at a distance look very blurry. Even more fuzzy picture we get when observing through the earth's atmosphere. The telescope of James Webb, in turn, is located far from the Earth and has a lens whose size is several times larger than that of the Hubble telescope. Because of this, there are ample opportunities to observe the comets of the Solar System.
James Webb also has an ultrasensitive spectrometer with a wavelength range of 3 to 5 microns. With it, we can explore the emissions of cometary gases - water vapor, carbon dioxide. Studying them, we can determine the composition of the cometary nucleus. “We want to understand what the core is made of,” said Kaylee in an interview with Discovery News. “From a distance, all we see is a bright, incoherent cloud. We have no opportunity to study the core directly. ”
Carbon dioxide in the tail of the NEAT comet (discovered in 2004) is not visible on images from the Earth.
Carbon dioxide in comets is practically not visible from the Earth, because dense layers of the atmosphere obscure the view. Using the James Webb telescope, we can see it very well. Why is it important? Because its presence is one of the main indicators for calculating the lost mass of a comet during its approach to the sun and with the loss of its outer layers.
Carbon dioxide and its close relative, carbon monoxide are volatile molecules. This means that they are easily exposed to solar energy, in comparison, for example, with ice. Therefore, when the comet approaches the sun, scientists want to study these two elements to understand the process of erosion.
Several comets were seen in the asteroid belt between Mars and Jupiter. Terrestrial telescopes spotted dust traces from these comets, a kind of cometary activity is supposed to occur there. Although, most likely, this activity is low. Given their relative proximity to the Sun and the stability of the orbit, it can be assumed that most of their gas has evaporated.
The sensitivity of the telescope by James Webb allows scientists to understand how much gas is left in the comets of the main belt. Kaylie said that this gas may be related to water. “These are stories about water in the asteroid belt,” he said. “We want to understand where it came from, how much it was, and how much in time it came to Earth.”
Most comets can be studied only in the vicinity of the Earth, because there are also vehicles for studying them. (“Rosetta” was the first device in orbit of the comet for more than one year). This creates a distorted view of comets. We see them only during a strong activity, and not during warming up or cooling.
Comet 103P / Hartley-2 (in the photo), along with an artistic illustration of its route in the Solar System. (2010)
The list of promising research objectives for “James Webb” is very wide, but here are some of Kelly's “favorites”:
- 46P / Wirtanen (2018): This comet passes very close to the Earth, approximately four times the distance from the Earth to the Moon. Kelly says that the combination of its closeness and good image of James Webb will allow scientists to study the comet's surface well;
- 133P / Elst-Pizarro (2018): One of the most famous comets in the main asteroid belt. Before the appearance of James Webb, there was no clear information about the amount of gas in these comets. “James Webb” will be able to provide it to us;
- 103P / Hartley 2 (2023): This comet was slightly explored in 2010 during the NASA mission, EPOXI. With the help of “James Webb” we can form a more accurate picture of the comet's behavior.