In 1930, Pluto was found and named a planet, when cosmologist Clyde Tombaugh of the Lowell Observatory compared photographic plates of the sky on different nights and saw a tiny dot that floated to and fro against the background of stars. Immediately, the nearby solar system’s latest candidate was viewed as something weird. Its orbit was so unique. It was far from circular, that it was really closer to the sun than Neptune for 20 of its 248-years-in length trip.

Pluto is circled by five known moons, the biggest of which is Charon. Charon is about half of Pluto’s size itself, making it the biggest satellite comparative with the earth. Charon and Pluto are most times called a “double planet”.

Pluto’s category as a planet has had a past filled with changes. Since 2006, per the International Astronomical Union’s planetary standards, Pluto isn’t viewed as a planet since it hasn’t got the neighborhood around its orbit free from different objects. Nevertheless, it meets IAU’s standards for what comprises a dwarf planet.

 At the IAU General Assembly conference in Prague in 2006, researchers persevered through eight days of combative contentions, with four different propositions being offered. One dubious recommendation would have acquired the complete number of planets in the solar system up to 12, including Pluto’s moon Charon and Ceres, the biggest asteroid.

Close to the end of the Prague conference, 424 astronomers cast a vote to make three new classifications for objects in the solar system. From that point on, just the worlds Mercury through Neptune would be viewed as planets. Pluto and other round objects that shared the neighborhood of their orbit with different substances were called dwarf planets. Other items circling the sun would be known as small solar system bodies.

According to the International Astronomical Union, the organization charged with naming all celestial bodies and deciding on their statuses, Pluto is still not an official planet in our solar system.

However, further observations determined that it was smaller than initially assumed. Also, after American astronomer James Christy discovered Pluto’s largest moon, Charon, in 1978, astronomers were able to determine Pluto’s mass and realized that it was lightweight and didn’t exert a gravitational influence powerful enough to have induced the observed perturbations. Pluto was found to be smaller and less massive than all the other planets. Moreover, its orbit is highly inclined (17 degrees) relative to the ecliptic, the plane defined by Earth’s orbit around the Sun. The other planetary orbits have smaller inclinations.     

According to the International Astronomical Union, the association charged with naming every celestial body and settling on their statuses with, Pluto is as yet not an official planet in our solar system. Not long after Pluto was found in 1930, it was established as a planet, the 10th in our solar system. After Pluto was found, numerous astronomers assumed it to have been responsible for the turmoils they have seen in Neptune’s orbit. It was these turmoils that really motivated the search for a planet beyond it. Nonetheless, further observations discovered that it was smaller than was initially expected.

NASA agreed to study two missions to Venus, aiming to study how Venus ends up becoming an inferno-like world even when its characteristics are close to our planet Earth.

Two selected missions are DAVINCI+ (Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging) and VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy).

DAVINCI+ mission will be responsible for measuring the composition of Venus’ atmosphere to understand how it formed and evolved, as well as determine whether the planet ever had an ocean. This mission will be responsible for finding the reason why Venus’s atmosphere is unlikely to Earth by plunging a decent sphere through the planet’s atmosphere.

VERITAS mission will be responsible for mapping Venus’ surface to determine the planet’s geologic history and understand why it developed so differently than Earth. A synthetic aperture radar will be placed in the orbit of Venus which will chart surface elevations over nearly the entire planet to create 3D reconstructions of topography and confirm whether processes such as plate tectonics and volcanism are still active on Venus. Mapping of infrared emissions from Venus’ surface to map its rock type, which is largely unknown, and determine whether active volcanoes are releasing water vapor into the atmosphere will also be done in this mission.

These two missions will support a selected pair of technology demonstrations to fly along with them.

VERITAS will host the Deep Space Atomic Clock-2, built by JPL and funded by NASA’s Space Technology Mission Directorate.

DAVINCI+ will host the Compact Ultraviolet to Visible Imaging Spectrometer (CUVIS) built by Goddard. CUVIS will make high-resolution measurements of ultraviolet light using a new instrument based on freeform optics.

References:

• https://www.nasa.gov/press-release/nasa-selects-2-missions-to-study-lost-habitable-world-of-venus
• https://solarsystem.nasa.gov/planets/dwarf-planets/pluto/in-depth/
• https://usm.maine.edu/planet/pluto-planet-again
• https://now.northropgrumman.com/pluto-discovery-debacle-is-pluto-a-planet-again/
• https://www.google.com/amp/s/www.space.com/amp/why-pluto-is-not-a-planet.html