NASA has chosen not one but two new spacecraft missions to investigate the sun's second planet. The projects included a probe that will plunge into Venus' atmosphere and an orbiter that will orbit above the Earth's "evil twin."

The astronomy community had been waiting all day for NASA to make an ambiguous announcement about future missions. Fortunately, Science Times reported that NASA would launch the missions at the end of this decade.

When NASA Administrator Bill Nelson said the word Venus, some planetary scientists lost it. But many planetary scientists were pleased with the choice. They believed that NASA had neglected Venus in favor of our other next-door friend, The Atlantic said.

One expedition would have been exciting enough, but two is almost bizarre. So here are some of the reasons why specialists are looking forward to these expeditions.

Descent Mission

Davinci+ (acronym of Deep Atmosphere of Venus Investigations of Noble Gases, Chemistry and Imaging) will be the first of the two NASA missions chosen. It has a descent probe, which means it will plummet through the atmosphere while taking measurements. NASA divided the descent into three stages, The Conversation said.

The first of which examines the entire atmosphere. The probe will study the atmosphere's composition in great detail, delivering data on each layer as it falls. For example, we know that sulphuric acid is restricted to cloud layers at the height of roughly 50 kilometers (30 miles). The atmosphere is 97 percent carbon dioxide.

However, examining trace components can reveal how the atmosphere came to be in this state. Therefore, the second stage will measure meteorological parameters such as wind speed, temperature, and pressure at lower altitudes.

The final stage involves taking high-resolution surface photographs. While this is a typical occurrence on Mars, it has always proven difficult on Venus. Because the dense cloud layer absorbs visible light, observation from Earth or orbit is not possible. Rovers are also impractical due to the harsh surface conditions. A balloon mission has been suggested as one option.

The Magellan mission, which used radar to scan the surface of Venus in 1990, generated a low-resolution image of the planet's surface. During its descent, the Davinci probe will use infrared light to take surface photos. These images will not only aid future mission planning. Still, they will also aid scientists in their investigation of how the surface arose.

ALSO READ: Venus Day Length: Experts Say Earth's Sibling Rotates Every 20 Minutes 

Mapping the Surface

Veritas, which stands for Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy, is the name of the second expedition. EastMojo said this is going to be a more typical planetary expedition. The orbiter will be equipped with two sensors that will map the surface in addition to Davinci's extensive infrared studies.

The first is a camera that can detect a wide variety of wavelengths. It has the ability to look past Venus's clouds in order to analyze the composition of the atmosphere and ground.

This is a tricky process since the reflected light has a wide variety of wavelengths due to the surface temperature. However, Veritas will compensate for this by employing techniques similar to those used to analyze extraterrestrial atmospheres.

Water vapor will also be detected using the wavelength camera. The Venus Express mission revealed that hydrogen and oxygen are the principal constituents departing the Venusian atmosphere, therefore any water there will be in trace amounts or deep beneath the surface.

The second instrument is a radar, which uses a commonly employed method on Earth observation satellites. Radio pulses shot at various angles in front of the spacecraft are used to simulate a very large active radio receiver needed for high-resolution photographs.

NASA will use the high-resolution radar photos to generate a more detailed map of Venus's surface evolution and see any tectonic or volcanic activity.

Two Missions To Support Claim Made 500 Million Years Ago

These missions could support a study that the Venusian surface melted and regenerated entirely 500 million years ago. This was proposed to explain the lack of meteorite strikes on the surface, but no evidence of a volcanic lava layer resulting from such resurfacing has yet been discovered.

The fact that NASA has shifted its planetary mission focus to Venus is fascinating. Unfortunately, experts claim there's no prospect of sending a human there any time soon for any aspiring astronauts. However, the knowledge gathered from Earth's largely forgotten sister will be precious in understanding our globe.

RELATED ARTICLE: Venus Emits Weird Audible Radio Signals as Heard by the NASA Parker Solar Probe [WATCH]  

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