The Hera mission, which follows NASA’s DART asteroid crash, recently spotted two asteroids while testing its camera. This is a key step before it reaches its main targets: Didymos and Dimorphos.
In September 2022, NASA’s Double Asteroid Redirection Test (DART) slammed into the smaller asteroid, Dimorphos. This experiment showed how we might divert potentially hazardous asteroids away from Earth.
Fast forward to October 7, 2024, when the European Space Agency (ESA) launched the Hera mission. It’s now headed toward Didymos and Dimorphos to closely observe the effects of the DART impact.
In March 2025, Hera had a close encounter with Mars, using its gravitational pull to speed through the asteroid belt. This journey has allowed Hera to test its instruments effectively. Giacomo Moresco, a Flight Dynamics Engineer at ESA, noted that Hera is performing well, enabling the team to practice and prepare for its asteroid observations.
Interestingly, the asteroid belt between Mars and Jupiter is mostly empty, which posed a challenge for Hera. ESA’s team worked for weeks to identify asteroids that Hera could image. They chose (1126) Otero and (18805) Kellyday, both faint and distant asteroids that would help simulate the conditions for spotting Didymos and Dimorphos.
Otero was the first target. Discovered in 1929, it’s a rare A-type asteroid known for its reddish color and olivine mineral. Hera tracked Otero for three hours, capturing images every six minutes. From 187 million miles away, it began to look like a small trail against the starry backdrop.
Next up was Kellyday, named for a high school student who won a science competition. This asteroid was 40 times fainter than Otero, making it a tougher challenge. Moresco mentioned that detecting Kellyday pushed the limits of Hera’s capabilities, but they successfully spotted it.
Imaging these asteroids was a great success that prepares Hera for its main mission. With these skills in hand, Hera could also monitor new or potentially hazardous asteroids that come into sight. This ability helps astronomers calculate their paths and assess any collision risks with Earth.
Moresco highlighted how this mission allows for rapid-response observations, building confidence for the science phase ahead. Hera is expected to arrive at Didymos and Dimorphos in late 2026, where it will spend six months studying the asteroids and DART’s impact.
