The satellite that has revolutionised our knowledge of climate change has returned from space

ERS-2 has returned home after almost 30 years and during its activity it has shocked our knowledge of the Earth and the changes that are affecting it. So let's find out something more about this incredible satellite.

satellites
The ERS-2 satellite has returned to the Earth's atmosphere.

A few days ago, exactly on February 21, at 18:17 Italian time, ESA's ERS-2 concluded its uncontrolled return to our planet. The impact occurred on the North Pacific Ocean, between Alaska and Hawaii.

It was precisely the European Space Agency (ESA) that announced that at the moment there is no news of the possible fall of debris, that is, fragments of satellite that are not completely disintegrated in the crossing of the atmosphere.

As we have already said in a previous article, the ERS-2 mission actually ended on 5 September 2011. Subsequently, the satellite was deorbited, that is, it dropped by altitude to 573 kilometers, so that within 15 years at the latest the satellite would actually re-enter our atmosphere without further increasing the amount of space debris in orbit around our planet.

An innovative and fundamental mission

In its more than 15 years of activity ERS-2 has contributed to the knowledge of our planet in an incredible way. In fact, it is a satellite for remote sensing, its name is the acronym for European Remote-Sensing satellite (ERS).

When it was launched, on April 21, 1995, it was among the most sophisticated Earth observation satellites ever developed. His mission began about 4 years after his sister satellite ERS-1, launched on July 17, 1991, and both departed for space aboard an Ariane 4 carrier, from the spaceport of Kourou in French Guiana.

The two satellites were then placed in a polar heliosynchronous orbit at an altitude of between 782 and 785 kilometers.

This specific type of orbit was chosen because it allows the satellites that perform it to pass over both Earth poles and to pass over each point always at the same local time, in this way observations of the Earth can always be made under the same conditions of solar illumination. This is essential in order to be able to monitor in a very precise way the possible changes on the land surfaces and the seas.

In order to succeed in the enterprise of collecting as much information as possible about the Earth, thus analyzing land, water, ice and atmosphere, the satellites had a variety of instruments truly state-of-the-art for the period: a Ku-band altimetric radar, a four-channel infrared radiometer capable of measuring the temperature of both seas and clouds, a microwave analyzer, a synthetic aperture radar (SAR) for images and a scatterometer, or a wind meter.

Polar ice cap
Thanks to ERS-2 we were able to observe the reduction of the polar caps.

The ATSR-2 (Along Track Scanning Radiometer) radiometer among other things was also able to make measurements related to vegetation and chlorophyll. In addition, ERS-2 also had a GOME (Global Ozone Monitoring Experiment), which is an absorption spectrometer designed to study the chemical composition of the atmosphere and in particular to measure atmospheric ozone.

A peculiarity of these two missions is that the satellites were spaced a day away, so a day after the passage of ERS-1 also took place the passage of ERS-2.

These satellites have revolutionized our knowledge

Thanks to the continuous and constant observation of our planet, these revolutionary satellites have collected an incredible amount of data on decreasing polar ice, changes in land surfaces, sea level rise, ocean warming and atmospheric chemistry.

Obviously the notion of climate change was already known but much less known and understood than today. It is thanks to these satellites that we had yet another, glaring proof. These missions provided us with previously unknown elements about it and thus gave scientists the data that helped to understand the impact humans are having on the planet.

The twin satellites have also been used to monitor some natural disasters, such as severe floods and/or earthquakes even in the most remote and inaccessible parts of the Earth.

Obviously given the enormous achievements and successes achieved by these jewels of technology, subsequent missions such as MetOp weather satellites, the Envisat mission, but also Earth Explorer, Copernicus Sentinel and many others have also been based on them.

With the ERS satellites it has become clear the need to have routine, constant observations, in order to be able to be aware of the variations in progress.

ESA also has a space program, Heritage, which ensures that data from inactive satellites continues to be used, so it is very likely that further discoveries can be made in the near future thanks to ERS-2.