Earth is an extraordinarily solitary planet.
The European Space Agency’s (ESA) Hera spacecraft, en route to an asteroid, recently captured breathtaking imagery of Earth and the moon against the vastness of space. The visuals depict the two celestial entities gradually diminishing as Hera moved from around 860,000 miles to 2.4 million miles (1.4 to 3.8 million kilometers) away in October.
“As #HeraMission distanced itself from its home planet, it observed the Moon revolving around Earth,” ESA mentioned in a post.
For reference, the moon is situated approximately 239,000 miles from Earth.
Our solar system is similarly quite isolated. The spaces between stars are immense. “In fact, if the sun were to be reduced to the size of a grain of sand, the nearest star would be measured in miles,” elucidated Sally Dodson-Robinson, a planetary scientist from the University of Delaware. The closest solar system, Alpha Centauri, is around 25 trillion miles from Earth.
Nonetheless, the Hera spacecraft is not straying too far in cosmic proportions. It is set to meet the asteroid Dimorphos in December 2026, which will be roughly 121 million miles (195 million kilometers) from Earth at that time. This endeavor is part of a planetary defense strategy: Hera will employ advanced cameras and instruments to analyze the impact site of NASA’s successful asteroid-deflection experiment. This experiment proved that humanity can change the trajectory of a potentially hazardous asteroid. Dimorphos, which poses no risk to Earth, measures about 525 feet (160 meters) in width, comparable to a stadium.
ESA stated that by gathering comprehensive data on Dimorphos, which was struck by NASA’s DART spacecraft in 2022, Hera will enhance asteroid deflection methods, making them more dependable and possibly repeatable.
To brace for potential threats — like a significant asteroid or one that catches us off guard — scientists are also investigating the use of a nuclear device to modify an asteroid’s path. While there is no identified asteroid risk for at least the next hundred years, it’s prudent to be ready, even if the odds of an impact are minimal.
“You wouldn’t want to take risks with an asteroid the size of a city,” Nathan Moore, a physicist at Sandia National Laboratories, previously remarked to *Mashable*.