The rings of Neptune captured by James Webb Space Telescope after three decades

                         Rings of Neptune

Rings of Neptune!! Yes, you heard it correctly. We are all so familiar with the rings of Saturn, the countless small particles of different shapes and sizes that orbit around Saturn, giving a ring-like look. But very rarely do we find anybody speaking about the rings of Neptune. This is exactly what the James Webb space telescope has spotted. 

But this is not the first time that these rings have been visible to us. We knew about these rings earlier, but this is the first time we have received such a clear and crisp image of the rings of Neptune and this spotting has been possible after 30 years. 

                     James Webb Space Telescope

Neptune has always fascinated researchers since its discovery on 23rd September 1846 by Johann Galle. It is the only planet in the solar system which was discovered on the basis of mathematical prediction rather than by empirical observation. 

Alexis Bouvard observed that there were unexpected changes in the orbit of Uranus. From this, he hypothesized that the orbit of Uranus was subject to gravitational perturbations of an unknown planet, which was later found to be Neptune.

In 1989 Nasa's Voyager II spacecraft did a flyby past Neptune and during this time it captured the planet's rings. After that Voyager II continued its journey in interstellar space beyond the solar system, so no more images of these rings could be captured. 

The recent images captured by the Webb show Neptune's fainter dust bands in addition to several bright, narrow rings. It should be noted that Neptune is located 30 times farther from the Sun than Earth and its orbits are located in the remote darker regions of the solar system. Moreover, due to its chemical composition, it is generally referred to as an ice giant, in contrast to the gas giants like Jupiter and Saturn.

           

                    Hubble Space Telescope

The images of Neptune captured by the Hubble space telescope (images at visible wavelength) have a bluish tinge due to the presence of small amounts of gaseous methane. But the James Webb space telescope captured Neptune in its near-infrared range which gave the planet a purple tinge instead of blue. 

Apart from these, Webb has also captured 7 out of 14 moons of Neptune. There is a very bright point seen in the image captured by the Webb, which is Neptune's large and unusual moon Triton (it orbits Neptune in a strange backward orbit). Triton reflects more than 70% of the sunlight that is incident on it. Moreover, due to methane absorption, the planet's atmosphere is darkened at near-infrared wavelengths. The combined effect is that Triton quite easily outshines Neptune in the image. The image from Webb has also revealed a continuous band of high-latitude clouds surrounding the planet, which was never seen before.

By

Prabir Rudra

 

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TOI-1452b: An Earth-like planet with deeper oceans and two suns.

 

Recently NASA discovered an exoplanet orbiting around two suns outside our solar system in the Draco constellation. It is named TOI-1452b and is 70% larger in size compared to Earth. The most striking feature of the planet is that it is covered with oceans considered to be deeper than those on Earth. But the feature that arouses the greatest interest is that the planet is situated in the habitable region of the parent stars and water on it remains in a liquid form unlike many moons in our solar system.

This super-earth was discovered two years ago by the TESS space telescope. The planet orbits a binary star system that has currently collapsed to its dwarf stage. So they are around four times smaller than the sun. The revolution speed of the planet is extremely high and so a year on this planet lasts for only 11 days. The orbit of the exoplanet is smaller compared to Earth separated by only 97 astronomical units. Moreover, it is cooler but receives enough light to sustain life.

Researchers have estimated a total ocean presence of around 30% of the total mass. This is huge compared to that of Earth because Earth's 70% water regions only make up about 1% of the total mass. The massiveness of the planet suggests that the depths of the oceans will be far greater than those on Earth. So from this, we can understand the huge reservoir of water that this planet holds. To add to this, all the water present on this planet is in liquid form, which is a real advantage. We know that Jupiter's two moons Ganymede and Callisto contain deep oceans, but they are buried deep beneath thick sheets of ice. The same applies to Saturn's moons Titan and Enceladus.

                 Jupiter and its moon Ganymede

                        Titan: Saturn's moon

To draw some concrete inferences, scientists need to get more observations from powerful telescopes like the James Webb. It is theorized that life originated under the oceans near the hydrothermal vents. Considering this, presence of such a huge amount of water are really positive signs for us. Although scientists are of the idea that the planet does not have an atmosphere, we know that the planet can be brimming with life. This is because some of the branches of the oldest bacteria can live in extreme environments. So in all, the exoplanet is of great interest to us and can be significant in shaping the future of humanity.

                       Bacteria

by

Prabir Rudra

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