UPSC PRELIMS+ IAS MAINS
1. Dwarf Planet Ceres is now an ‘ocean world’
What does this mean?
Context: Researchers have shed new light on the dwarf planet Ceres, which lies in the asteroid belt between Mars and Jupiter and is also the largest object in that belt.
- Ceres now has the status of an “ocean world”, after scientists analyzed data collected by NASA’s Dawn spacecraft and have determined that Ceres has a brine reservoir located about 40 km deep and which is hundreds of miles wide, making the dwarf planet, “water-rich”.
What is a dwarf planet?
- There are officially five dwarf planets in our Solar System. The most famous is Pluto, downgraded from the status of a planet in 2006.
- The other four, in order of size, are Eris, Makemake, Haumea and Ceres.
- With the exception of Ceres (the only dwarf planet located in the inner solar system), which is located in the asteroid belt, the other dwarf planets are found in the outer solar system.
- Of the dwarf planets, only 2 have been visited by space probes, in 2015 NASA’s Dawn and New Horizons missions reached Ceres and Pluto respectively.
- The order of the dwarf planets from closest to Sun outwards is Ceres, Pluto, Haumea, Makemake, with Eris being the furthest from the Sun.
- The sixth claimant for a dwarf planet is Hygiea, which so far has been taken to be an asteroid.
- Last year, using observations made through the European Space Organisation’s SPHERE instrument at the Very Large Telescope (VLT), astronomers found that Hygiea may possibly be a dwarf planet since it satisfied the four criteria set by the International Astronomical Union (IAU) for a celestial body to be called a dwarf planet. These four criteria are –
- That the body orbits around the Sun;
- It is not a moon;
- Has not cleared the neighborhood around its orbit (which means it is not the dominant body in its orbit around the Sun and this is what differentiates a planet from a dwarf planet); and
- has enough mass for its gravity to pull it into a roughly spherical shape.
The dwarf planet is a lot like regular planets:
- They both have enough mass and gravity to be nearly round – unlike odd-shaped asteroids.
- They both travel through space in a path around the sun.
The big difference?
- A dwarf planet’s path around the sun is full of other objects like asteroids and comets.
- A regular planet has a clear path around the sun. Most of the major impacts with other objects in its orbit happened billions of years ago. There is not much left over to get in the way.
Ceres exploration in the past: Dwarf planet
- The dwarf planet was first spotted by Giuseppe Piazzi in 1801, who assumed that Ceres was the missing planet between Mars and Jupiter.
- Ceres was classified as a dwarf planet in 2006 and is the first dwarf planet to be orbited by a spacecraft.
- In 2015, NASA’s Dawn went into the orbit around Ceres and the information it collected reinforced the idea that dwarf planets could have hosted oceans over a significant part of their history.
Why do researchers study Ceres?
- Scientists are interested in this dwarf planet because it hosts the possibility of having water.
- Another reason why scientists are interested in the dwarf planet Ceres is because studying it can give insights about the formation of the Solar System since it is considered to be a fossil from that time.
- Significantly, an ocean world in Ceres was not expected, since it is too far away from the Sun and is too small to have radioactive materials to keep the oceans liquid for most of the dwarf planet’s history.
- Ceres can then be added to the rather short list of bodies for which we know the interior structure at high resolution (Before the mission ended in October 2018, the Dawn spacecraft dipped to less than 35 km above the surface of the dwarf planet, due to which it was able to collect data in a higher resolution), and the only ocean world to date (bar Earth).
- There are other dwarf planets and moons in our solar system where oceans exist, including the moons of Saturn and Jupiter.
Very Large Telescope array (VLT)
- It is the world’s most advanced optical instrument, consisting of a series of telescopes working together, to form a giant ‘interferometer’, the ESO Very Large Telescope Interferometer, allowing astronomers to see details up to 25 times finer than with the individual telescopes.
- Very Large Telescope (VLT) is an observatory located on the mountain Cerro Paranal in Chile.
Did you know?
- When astronomers combine the light waves from two telescopes using the principle of interferometry, they can very precisely determine the direction of an object in space.
- Your ears work in a similar way to localize sounds, by comparing the sound received at the left and right ears.
What is an Interferometer?
- Interferometers are ground-based stations and work by merging two or more sources of light to create an interference pattern, which can be measured and analyzed.
- They are often used to make very small measurements that are not achievable any other way.
- This is why they are so powerful for detecting gravitational waves–LIGO’s interferometers are designed to measure a distance 1/10,000ththe width of a proton!
2. What is Space Bricks?
- Context: In a significant step towards space exploration, a team of researchers from the Indian Space Research Organisation (ISRO) and the Indian Institute of Science (IISc) Bengaluru has developed a sustainable process to make space bricks on the lunar surface.
- The process enables making load-bearing bricks by using lunar soil, urea sourced from human urine, bacteria and guar beans.
- Since guar gum is used instead of cement, there will be a lower carbon footprint.
- The bacteria is added to further crystalise the brick in any shape needed.
- Named as space bricks, it could be used to assemble structures for habitation on the moon surface in future.
- Sending bricks from Earth is not viable as it takes Rs 7.5 lakh to transport one pound of construction material.
Source: Indian Express
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