Mars is the “Exploration Planet” targeted by the U.S., China, India, and soon Japan, utilizing rovers, landers, orbiters, and even a helicopter. It is also being explored by a country that did not exist when Neil Armstrong walked on the Moon. The United Arab Emirates (UAE) is new to planetary exploration with its space program hardly twelve years old, but their very first mission is proving to be a spectacular success. It selected Mars as the first planet to explore but did not want to duplicate missions from other countries with the orbiter it was planning. With all the exploring Mars has had during the past decades with over a dozen spacecraft, it may have seemed difficult to design an original new mission. Then came Hope.

The UAE designed Hope to obtain a comprehensive view of the Martian atmosphere and answer specific questions about its climate and weather. Current spacecraft orbit too close to Mars to give a broad, global view of the weather, even though they have been great for observing local weather such as dust storms in fine detail. Hope was launched on July 19, 2020, and entered orbit around Mars on February 9, 2021. The mission that was planned to last a complete Martian year (687 Earth days) exceeded that goal in 2023. It has made daily observations of the whole atmosphere and tracked how it changes between seasons. This information will help improve global circulation models. Hope is in a high orbit ranging from 12,400 to 26,700 miles where it can see the entire planet, including the flow of particles escaping into space and can watch global weather patterns evolve.

Most spacecraft are in time-locked orbits observing Mars at the same time every day, but Hope can observe Mars all hours of its day which makes it possible to observe variations in water vapor, water ice, and dust on a daily and seasonal basis. Hope has been able to track several weeks-long regional dust storms. The global coverage combined with hourly observations allow researchers to track the amount of dust storms contain and how it is distributed across the planet. This gives a better understanding of how dust affects the climate. The monitoring of cloud patterns has shown they tend to form early in the morning and dissipate by midday. Orographic clouds near the largest volcanoes are seen varying with the seasons and reduce the amount of heat radiated back into space from the surface. Viewing Mars at infrared, visible, and ultraviolet wavelengths on a global scale is giving scientists a new, more detailed perspective.

To achieve the scientific objectives of the mission, Hope is equipped with three scientific instruments. The Emirates Exploration Imager (EXI) is a multiband camera capable of taking high-resolution images with a resolution better than five miles. It uses a selector wheel mechanism consisting of six bandpass filters of which three are ultraviolet (UV) and three are visible: red, green, and blue (RGB). EXI measures properties of water, ice, dust, aerosols, and ozone in the atmosphere. The Emirates Mars Infrared Spectrometer (EMIRS) is an interferometric thermal infrared spectrometer that measures the emitted radiance from the surface and atmosphere, thus determining the surface and atmospheric temperature profiles, along with the abundance of ice, water vapor, and dust. EMIRS provides a view of the lower and middle atmosphere. The Emirates Mars Ultraviolet Spectrometer (EMUS) is the key instrument designed to study the Martian upper atmosphere, which is composed of the thermosphere layer, and the corona where hydrogen is formed from the dissociation of Mars’ water and is escaping into space under the influence of solar radiation and wind.

One of the biggest achievements for Hope so far is the discovery concerning Mars’ aurorae. Mars does not have a global magnetic field that can interact with the solar wind, but the thin atmosphere can. The crust has local magnetism from an earlier time when the magnetic field was global, therefore aurora can occur at any location regardless of latitude, and they are bright. Patchy aurorae not tied to the crust can also occur anywhere along with diffuse aurora which occur at lower altitudes. The sinuous discrete aurora is a new type of aurora not tied to any magnetism, appears long and ropey, and occurs mainly near the day/night terminator in the evening. Hope also discovered different types of aurorae occurring at the same time offering a window into the dynamic interplay between the solar wind and Mars’ atmosphere. It is not known if an aurora would be visible to anyone standing on the surface, but the Perseverance rover was able to faintly image them on March 15, 2024, when there was a massive solar storm.

Spacecraft orbit Mars so close that they never venture too far beyond the orbit of the larger moon, Phobos, but Hope is positioned so that even though it cannot get close to Phobos, it can get very close to the smaller moon, Deimos. It has taken advantage of this having flown past it several times as close as 64 miles. Hope has fully mapped Deimos at a resolution of 30 feet and provided the first look at its farside. High resolution spectroscopy has revealed details of its composition and temperature, hinting that it is made of the same stuff as Mars. Deimos lacks the carbon-rich minerals of asteroids and consists of basalt, an abundant volcanic rock on Mars. These findings go against the asteroid capture theory for Phobos and Deimos.

Hope has fulfilled its goal of inspiring the exploration of the Solar System as the United Arab Emirates has approved a new mission with broader goals. A mission to the asteroid belt is under development that will be a groundbreaking mission to explore and study seven asteroids to gain a better understanding of the formation of the Solar System. The spacecraft is scheduled to launch in March 2028 with the first asteroid encounter in February 2030, then past a rather large, 27-mile diameter asteroid, 623 Chimaera, in June 2030, then past four more smaller asteroids between 2031-2033, before slipping into orbit around 269 Justitia in October 2034. It will attempt to land on this 33-mile diameter asteroid (seen by this author on July 2, 2005) in May 2035.

Hope gets its name for hoping to inspire youth to study science and explore space. All the data gathered from Hope is publicly available. The best is the full global image of Mars in natural color that only Hope can obtain. That is inspiring!