Author: admin

The European Space Agency (ESA) and its partners have confirmed the successful launch of the Airbus-built Sentinel-4, a cutting-edge air quality monitoring instrument hosted on the third generation Meteosat (MTG-S1) weather satellite. The launch proceeded as planned and marks a significant advancement in Europe’s Earth observation capabilities.

“The successful launch of Sentinel-4 on board MTG-S1 is further proof of the innovation and successful collaboration within the European space sector,” said Alain Fauré, Head of Space Systems at Airbus. “The data provided by Sentinel-4 will be an essential contribution to the Copernicus programme, helping us to monitor, and ultimately improve air quality for citizens across Europe.”

Sentinel-4, developed in Germany on behalf of ESA, is a UV-VIS-NIR spectrometer that will deliver unprecedented high temporal resolution data on the composition of Earth’s atmosphere. Key measurements will include nitrogen dioxide, ozone, sulphur dioxide, and formaldehyde, as well as aerosols. This data is crucial for monitoring air quality across Europe, forecasting air pollution events, and understanding long-term changes in the atmosphere. 

The integration of Sentinel-4 onto the MTG weather satellite provides a unique opportunity for the simultaneous observation of weather phenomena and atmospheric chemical composition. This synergistic data acquisition will contribute to more accurate weather forecasts and a better understanding of the interactions between weather and climate.

The MTG satellite, carrying Sentinel-4, will be positioned in geostationary orbit 36,000 kilometres above the Earth. From this vantage point, Sentinel-4 will provide hourly data over Europe and North Africa. The data will be made freely and openly available through the Copernicus programme, serving a wide community of users, including scientists, environmental agencies, and policymakers.

The launch of Sentinel-4 is a key step in realising the objectives of the Copernicus programme, which aims to provide accurate and reliable Earth observation data to understand and address environmental challenges, ensure safety, and mitigate the impacts of natural disasters. The second Sentinel-4 is under integration and will fly on board MTG-S2 to be launched in the 2030s. 

Both the spacecraft and the instrument will be operated by EUMETSAT, the European Organisation for the Exploitation of Meteorological Satellites. The Sentinel-4 instrument builds on the experience of previous proven ESA instruments like SCIAMACHY and TROPOMI (on-board Sentinel-5P) also built by Airbus.

The MTG-S1 meteorological observation satellite was successfully launched from Cape Canaveral, Florida. Built by OHB System AG, MTG-S1 carries Europe’s first hyperspectral infrared sounding instrument designed for geostationary orbit. Thales Alenia Space, the joint company between Thales (67%) and Leonardo (33%), is responsible for the development, assembly, integration and testing of the main payload, which includes a high-precision interferometer and an advanced infrared detection system.

About MTG-S1

The primary objective of the MTG-S1 sounding satellite is to improve Europe’s numerical weather prediction (NWP) capabilities, both at regional and global scales. Thanks to its hyperspectral infrared sounding instrument, MTG-S1 enables 3D mapping of the atmosphere by precisely measuring temperature and humidity across latitude, longitude and altitude. These measurements will enable forecasters to detect the early warning signs of storms and will improve NWP models.

MTG-S1 also carries the Copernicus Sentinel-4 instrument, built by Airbus Defence and Space, which is dedicated to monitoring air quality and greenhouse gas concentrations from space. This instrument is equipped with an ultraviolet, visible and near-infrared spectrometer.

The combination of these two instruments will contribute to improved air quality forecasting and will provide a wealth of information for the benefit of public health, agriculture and scientific research.

About the MTG program 

The MTG-S1 satellite is part of the Meteosat Third Generation (MTG) program, developed by Thales Alenia Space as prime contractor for the European Space Agency (ESA) and the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT).

This program will ensure the continuity of European weather monitoring beyond 2040. It is based on a constellation of six satellites: four imaging satellites (MTG-I), built by Thales Alenia Space, and two atmospheric sounding satellites (MTG-S), developed by OHB. 

The MTG-I imaging satellites carry latest-generation instruments, including lightning detectors, built by Leonardo, and the FCI imager, which can deliver weather data in near-real time. The first satellite in the series, MTG-I1, was launched in 2022 and returned its first images in 2023, demonstrating a significant improvement over previous generations. 

The system provides updated images of Earth every 10 minutes (compared with 15 minutes previously) and delivers images over Europe every 2.5 minutes in rapid scan mode. 

“The Meteosat Third Generation constellation will profoundly transform weather forecasting capabilities by providing a more frequent, accurate and comprehensive picture of atmospheric phenomena,” said Bertrand Denis, VP Observation, Science and Exploration for Thales Alenia Space. “Once all six satellites are fully operational in orbit, EUMETSAT will have some of the most advanced forecasting capabilities in the world.” 

Half a century of geostationary weather satellites

Thales Alenia Space has been prime contractor for three generations of Meteosat satellites since the launch of the first flight model in 1977. The company built seven first-generation Meteosat satellites, four second-generation satellites, and is leading the development of the six third-generation satellites as prime contractor. It is also involved in the development of the ground segment for EUMETSAT, through the design and delivery of the Image Data Processing Facility. Telespazio, the joint company between Leonardo (67%) and Thales (33%), is also involved in the ground segment, both in data acquisition and satellite command and control. In addition, it will provide EUMETSAT with launch and early orbit phase (LEOP) services for two satellites, with an option for a third.

Since 1977, Meteosat satellites have been the main source of meteorological data for Europe and Africa. The data from these satellites is one of ESA and EUMETSAT’s key contributions to the World Meteorological Organization’s Global Observing System.

PARIS, July 3 — Why is Mars barren and uninhabitable, while life has always thrived here on our relatively similar planet Earth?

A discovery made by a Nasa rover has offered a clue for this mystery, new research said yesterday, suggesting that while rivers once sporadically flowed on Mars, it was doomed to mostly be a desert planet.

Mars is thought to currently have all the necessary ingredients for life except for perhaps the most important one: liquid water.

However, the red surface is carved out by ancient rivers and lakes, showing that water once flowed on our nearest neighbour.

There are currently several rovers searching Mars for signs of life that could have existed back in those more habitable times, millions of years ago.

Earlier this year, Nasa’s Curiosity rover discovered a missing piece in this puzzle: rocks that are rich in carbonate minerals.

These “carbonates” — such as limestone on Earth — act as a sponge for carbon dioxide, pulling it in from the atmosphere and trapping it in rock.

A new study, published in the journal Nature, modelled exactly how the existence of these rocks could change our understanding of Mars’s past.

Brief ‘oases’

Lead study author Edwin Kite, a planetary scientist at the University of Chicago and a member of the Curiosity team, told AFP it appeared there were “blips of habitability in some times and places” on Mars.

But these “oases” were the exception rather than the rule.

On Earth, carbon dioxide in the atmosphere warms the planet. Over long timescales, the carbon becomes trapped in rocks such as carbonates.

Then volcanic eruptions spew the gas back into the atmosphere, creating a well-balanced climate cycle supportive of consistently running water.

However, Mars has a “feeble” rate of volcanic outgassing compared to Earth, Kite said. This throws off the balance, leaving Mars much colder and less hospitable.

According to the modelling research, the brief periods of liquid water on Mars were followed by 100 million years of barren desert — a long time for anything to survive.

It is still possible that there are pockets of liquid water deep underground on Mars we have not yet found, Kite said.

Nasa’s Perseverance Rover, which landed on an ancient Martian delta in 2021, has also found signs of carbonates at the edge of dried-up lake, he added.

Next, the scientists hope to discover more evidence of carbonates.

Kite said the best proof would be returning rock samples from the Martian surface back to Earth — both the United States and China are racing to do this in the next decade.

Are we alone?

Ultimately, scientists are searching for an answer to one of the great questions: how common are planets like Earth that can harbour life?

Astronomers have discovered nearly 6,000 planets beyond our Solar System since the early 1990s.

But only for Mars and Earth can scientists study rocks which allow them to understand the planet’s past, Kite said.

If we do determine that Mars never hosted even tiny micro-organisms during its watery times, that would indicate it is difficult to kick-start life across the universe.

But if we discover proof of ancient life, that would “basically be telling us the origin of life is easy on a planetary scale,” Kite said. — AFP