Science and Tech

Why should we go back to Venus?

Why should we go back to Venus?


Very close to us, cosmologically speaking, there is a planet that is almost identical to Earth. Venus is about the same size, made of more or less the same stuff, and has formed around the same star.

For an alien astronomer light-years away looking at the solar system through a telescope, it would be virtually impossible to distinguish Venus from our planet.

However, when the surface conditions From Venus – furnace temperature and carbon dioxide-saturated atmosphere with clouds of sulfuric acid – it is clear that Venus is nothing like Earth.

How is it possible that two planets so similar in terms of position, formation and composition can end up being so different? It’s a question that concerns a growing number of members of the planetary science community, and prompts numerous initiatives to explore Venus.

If the scientific community can understand why it evolved as it did, we will know with more certainty whether the existence of an Earth-like planet is the rule or the exception.

Was Venus a blue planet in another time?

Current scientific opinion holds that, at some point in the past, Venus had much more water than its dry atmosphere suggests today, maybe even oceans. But as the Sun got hotter and brighter (due to natural aging), the surface temperatures of Venus rose and eventually evaporated the oceans and seas.

The increasing accumulation of water vapor in the atmosphere created on the planet conditions of runaway greenhouse effect from which Venus failed to recover.

It is not known whether there was ever on Venus Earth-like plate tectonics (where the outer shell of the planet is broken into large moving pieces). Water is essential for plate tectonics to work, and a runaway greenhouse effect would effectively stop that process, if it ever took place there.

But the end of plate tectonics would not have meant the end of geological activity: the planet’s considerable internal heat continued to produce magma, which spilled out in the form of voluminous lava flows and reconfigured most of its surface.

In fact, the average age of its surface is about 700 million years, an old age, no doubt, but very young if we compare it with the surfaces of Mars, Mercury or the Moon, which are several billion years old.

exploration of the second planet

The view of Venus as a wet world is just a hypothesis: the planetary science community doesn’t know what made Venus so different from Earth, or whether the two planets were actually generated under the same conditions.

Humans know less about Venus than we do about the other planets in the inner solar system, largely because Venus poses several unique obstacles to exploration.

For example, it is necessary to explore it by means of Radar to pierce the opaque clouds of sulfuric acid and see the surface. The difficulty is much greater than with the surfaces of the Moon or Mercury, which can be easily observed.

In addition, the high temperature of the surface –470℃– makes conventional electronics last only a few hours. A very different situation from Mars, where the rover can operate for more than ten years. Thus, due in part to the heat, acidity, and opacity of the surface, Venus has not enjoyed a sustained program of exploration in the past two decades.

However, in the 21st century two missions have been sent to Venus: the Venus Express satelliteof the European Space Agency, which operated between 2006 and 2014, and the akatsuki probefrom the Japan Aerospace Exploration Agency, which is currently in orbit.

Little interest

Human beings have not always shown so little interest in Venus. It was once the darling of planetary exploration: between 1960 and 1980, some 35 missions were sent to the second planet. The mariner mission 2 It was the first space probe to successfully conduct a planetary rendezvous, flying over Venus in 1962.

The first images taken from its surface sent by the Soviet Venera 9 probe module after landing on Venus in 1975. And the Venera 13 lander it was the first space vehicle that sent sounds from its surface.

But the last mission NASA launched to Venus was the Magellan probein 1989. This probe took radar images of virtually the entire surface before its predicted disappearance from the planet’s atmosphere in 1994.

Go back to Venus?

Several NASA missions to Venus have been proposed in recent years. The most recent planetary mission that NASA has chosen is a nuclear-powered spacecraft called Dragonfly bound for the moon Titan, on Saturn, but a proposal aimed at measuring the composition of the surface of Venus has also been selected, that you will receive support to further develop your technology.

Other missions in the study phase are a project of the European Space Agency that aims to map the surface of Venus in high resolution and a plan From Russia What is proposed reinforce the legacy he left as the only country that has managed to place a lander on the surface of Venus.

Some 30 years after NASA set sail for our nefarious neighbor, the future of exploring Venus looks promising. But sending only one mission – an orbiter with radar or even a long-duration lander– not all pending mysteries will be solved.

Rather, a sustained program of exploration is needed to raise our knowledge of Venus to the level of knowledge we have of Mars or the Moon. To achieve this, it will be necessary to invest time and money, but, in my opinion, it is worth it.

If we can figure out why and when Venus became the planet it is today, we will better understand how an Earth-sized world can evolve. when it is located near its star. And, under an increasingly bright Sun, Venus may even help us understand the fate of Earth itself.

Font: Paul K. Byrne / THE CONVERSATION

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