Syllabus:
GS-3: Awareness in the fields of IT, Space, Computers, robotics, nano-technology, bio-technology and issues relating to intellectual property rights.
Context:
Astronomers have recently discovered an asteroid 2025 PN7, the earth’s latest quasi-satellite.
Asteroid 2025 PN7
- It is a small asteroid revolving around the Sun while remaining near Earth.
- The team found that 2025 PN7 had been in a quasi-orbit for about 60 years already and would likely be nearby for another 60 or so years before departing.
- It was first spotted in August by the Pan-STARRS 1 telescope in Hawaii.
- It is a member of the Arjuna asteroid class. It is just 62 feet wide, observable only with high powerful telescopes.
- 2025 PN7 follows an orbit very similar to that of the earth, making it appear to ‘hover’ nearby even though it’s not gravitationally bound to the planet.
- According to a researcher, 2025 PN7 is also the earth’s seventh known quasi-satellite.
Quasi-Satellite:
- A quasi-satellite is a small body in a 1:1 orbital resonance with a planet, maintaining proximity to it over many orbital periods while orbiting the Sun rather than the planet itself.
Arjuna Asteroid Class
- Arjuna asteroids are a dynamical class of near-Earth objects (NEOs).
- They have Earth-like orbits, meaning their semi-major axis, eccentricity, and inclination are very close to Earth’s.
- This feature allows them to stay near Earth for long periods and sometimes act as quasi-satellites or temporary companions.
- The broader interest stems from the Arjuna asteroid class, first hinted at with the discovery of asteroid 1991 VG more than three decades ago.
- Today, astronomers are aware of more than 100 such Arjunas, which together form a secondary asteroid belt.
Notable Examples:
- 2014 OL339 – A temporary quasi-satellite of Earth.
- 469219 Kamoʻoalewa (2016 HO3) – Often called “Earth’s constant companion.”
- 2025 PN7 – The newest reported Arjuna-class asteroid, identified as a quasi-moon.
Significance of the Findings
- Advancing Scientific Knowledge: Its presence adds to astronomers’ understanding of the shifting population of asteroids near Earth.
- Strengthening Planetary Defense: Asteroids like 2025 PN7, which stay near Earth for long durations, provide an ideal testbed to refine tracking and deflection strategies, including techniques such as kinetic impactors and gravity tractors.
- Resource Utilisation: Quasi-satellites like 2025 PN7 may contain valuable resources such as water ice and metals, making them potential targets for asteroid mining and in-situ resource utilization (ISRU) to support long-term human presence in space.
- Stepping Stone for Deep-Space Missions: It can serve as nearby proving grounds for life-support, resource use, and deep-space propulsion, offering practice for crewed Mars missions and asteroid redirection projects.
Pan-STARRS 1 telescope
- The Pan-STARRS 1 (PS1) telescope is a key component of the Pan-STARRS (Panoramic Survey Telescope and Rapid Response System) project, designed for wide-field astronomical imaging, particularly for finding and tracking near-Earth objects (NEOs).
- It is a 1.8-meter diameter telescope located near the summit of Haleakala on the Island of Maui. It is equipped with the world’s largest digital camera, with almost 1.4 billion pixels.
- The telescope observes in multiple wavelength bands, including visible and near-infrared light.
- The system’s capabilities help in spotting supernovae and other sudden astronomical events.
- Data from PS1 also contributes to the study of outer solar system objects like Kuiper Belt objects and centaurs.
Sources:
The Hindu
Explainers
Hawaii.