NASA’s Transiting Exoplanet Survey Satellite (TESS) mission discovered two rocky exoplanets – TOI-2322 b and TOI-2322 c. They orbit a K-type star (TOI-2322) located ~195 light years away from Earth. This discovery adds valuable insights into rocky planet formation and expands our understanding of Earth-like exoplanets.
About TOI-2322 Star System
- Host Star: TOI-2322 (also known as TIC 300812741).
- Star Type: K4-type (smaller & cooler than the Sun).
- Size & Mass: ~30% smaller & less massive than Sun.
- Temperature: 4,664 K.
- Age: ~3.9 billion years.
- Distance from Earth: 195 light years.
- Observation Period: 2018–2023 (via TESS).
- Discovery Team: Led by Melissa Hobson, University of Geneva.
Details of the New Exoplanets
TOI-2322 b
- Size: Earth-sized.
- Mass: < 2.03 Earth masses.
- Orbit: 11.3 days.
- Distance from Star: 0.09 AU.
- Temperature: ~603 K (extremely hot).
- Nature: Rocky, Earth-like in size but not habitable.
TOI-2322 c
- Size: 1.87 × Earth radius.
- Mass: 18 × Earth mass.
- Density: 14.69 g/cm³ (very high, similar to Earth’s rocky composition).
- Orbit: 20.2 days.
- Distance from Star: 0.13 AU.
- Temperature: ~500 K.
- Nature: Super-Earth, rocky, Earth-like internal structure.
Both planets are short-period rocky exoplanets, with TOI-2322 c being one of the largest known Earth-like composition super-Earths.
How TESS Detects Exoplanets
- Method: Transit photometry → monitors brightness of stars.
- Process: When a planet transits (passes in front of the star), TESS detects slight dimming.
- Equipment: Four wide-field cameras.
- Performance: Since launch (2018), TESS has:
- Surveyed ~200,000 stars.
- Identified 7,600+ exoplanet candidates (TOI).
- Confirmed 686 planets so far.
- Covered ~85% of the sky.
Importance of the Discovery
- Rocky Exoplanets: Rare finds that help study planetary formation & structures.
- TOI-2322 c: Exceptionally high density → key to understanding super-Earths.
- Follow-up Studies: Close enough for James Webb Space Telescope (JWST) to analyze atmospheres & conditions.
- Scientific Value: Helps test models of planetary activity vs transit signals (due to star’s rotation ~21 days).
- Big Question: Brings us closer to exploring habitability & diversity of planetary systems.
NASA’s TESS Mission & Future Prospects
- Launch: 2018.
- Goal: Search for transiting exoplanets around bright, nearby stars.
- Output: Thousands of candidates → roadmap for future telescopes.
- Next Steps:
- Deeper analysis with JWST & future missions.
- Study of planetary atmospheres & habitability potential.
Key Facts
- NASA (National Aeronautics and Space Administration): US space agency, established in 1958.
- NASA HQ: Washington D.C.
- TESS Mission: Launched in 2018, primary goal is to survey the brightest stars near Earth for transiting exoplanets.
- Exoplanet: A planet that orbits a star outside our solar system.
- Exoplanet Detection Method: Transit Photometry.
- Distance of TOI-2322 system: 195 light years.
- Light-Year: Distance light travels in one year (~9.46 trillion km).
- Super-Earth definition: Exoplanet larger than Earth but smaller than Neptune, with rocky composition.
- AU (Astronomical Unit): Distance between Earth and Sun (~150 million km).
- India’s Role in Space Science: ISRO also participates in exoplanet exploration with missions like AstroSat and plans for future space observatories.