Apophis T-4 Years: Knowledge Opportunity for the Science of Planetary Defense

Meteor Apophis will pass by Earth on April 13, 2029. This year, “T minus 4 years,” a workshop is April 9-10 in Tokyo, Japan, for researchers to discuss projects to protect Earth from asteroids, meteors and meteorites. Chelyabinsk Meteor in 2013, brighter than the Sun to viewers, exploded at altitude ~30km with estimated energy 30 times the Hiroshima bomb, injuring ~1,500 people, damaging ~7,200 buildings. The explosion of Tunguska in 1908 was ~1,000 times Hiroshima and destroyed ~2,000 square kilometers of forest, an estimated 80 million trees. Testimony of survivors was startling, of being thrown a few meters, feeling extreme heat and sound louder than thunder. “A similar-size impact event today could destroy a city the size of Kansas City.” Co-convenor of the workshop Richard Binzel, inventor of the Torino Scale that categorizes asteroid impact hazard, says Apophis offers a “once-per-thousand-year natural experiment…to significantly advance the science of Planetary Defense.” Asteroid 2873 Binzel bears his name. Co-convenor Patrick Michel belongs to the ESA Near-Earth Object Mission Advisory Panel and has asteroid 7561 PatrickMichel named for him. Co-convenor Seiji Sugita studies hypervelocity impact processes between planetary bodies. Workshop presenters will report on Apophis-focused space missions: ESA RAMSES, JAXA DESTINY+, ExLabs ApophisExL, Blue Origin Blue Ring, USRA Apophis Interceptor, Milo space Science Apophis Pathfinder, U of Maryland TERP RAPTOR, U of Arizona Apophis Precursor; Earth-based observations and international dialogue. (Image credits clockwise from upper L: Michel, Sugita, reddit, Binzel, Aleksandr Ivanov, Barringer Meteor Crater Enterprises, respective size graphic cmglee / Wagner51 / domdomegg)

MONDAY

☆ Apr 7 — International Space Station, ~415-km LEO: Expedition 72 crew … expecting arrival of 3 more crew launching on Soyuz MS-27.

☆ Apr 7 — Tiangong Space Station, ~390-km LEO: Shenzhou 19 three-member crew

☆ Apr 7 — Roscosmos, Launch Soyuz 2.1a / Soyuz MS-27, Baikonur Cosmodrome, Kazakhstan, Russia: To take Roscosmos Cosmonauts Sergey Ryzhikov and Alexey Zubritsky, and NASA Astronaut Jonny Kim to the International Space Station; 19:47 HST.

● Apr 7 — NASA, Online / Mountain View CA: 2025 Principal investigator applications due for NASA space mission proposal, Application No. NNH25ZDA009L, ahead of Aug 11-14 PI Launchpad In-Person Workshop 2025.

o Apr 7-11 — Deep Space Exploration Lab (DSEL), Hefei, China: 2025 International Conference of Deep Space Sciences.

● Apr 7-12 — Space Foundation, Colorado Springs CO: 40th Space Symposium; at the Broadmoor, standard registration US$3,260.

☆ Apr 7 — Pluto: At northernmost declination, 13:00.

☆ Apr 7 — Aten Asteroid 2003 GQ22: Near-Earth Flyby (0.050 AU)

Hawai’i 2025 Astro Updates

Hawai’i and its culture have significantly impacted astronomy on a global scale including ʻŌlelo Hawaiʻi names being given to celestial objects, such as Pōwehi, the first-ever imaged black hole M87*, the influence of native Hawaiian stellar navigation, and the ongoing and future science that comes from the facilities located on the mountains of Mauna Kea, Mauna Loa and Haleakalā. Pōwehi Day will be celebrated Apr 10 for the Event Horizon Telescope collaboration involving Mauna Kea Observatories. Alongside Pōwehi (adorned fathomless dark creation) for black hole M87*, Hawaiian names were given to celestial objects Laniakea (immeasurable heaven) for a supercluster of galaxies, Leleākūhonua (inspired by the bird, the kolea) for a dwarf planet, Kamoʻoalewa (sourced from the Kumulipo, alluding to a celestial object that is oscillating) for a near-Earth object, and ‘Oumuamua (scout) for the first interstellar asteroid to be discovered. For community involvement: on Apr 13 University of Hawai`i Institute for Astronomy is hosting its 2025 IfA Mānoa Open House, the Kamaʻāina Observatory Experience (by Maunakea Observatories and NOIRLab) is being held on upcoming weekends, Onizuka Center for International Astronomy has skygazing events including the MaunaKea Moon Mountains Observation program by ILOA Hawai’i, ʻImiloa Astronomy Center has a rich calendar featuring astronomy and astronautical programs, and Pacific International Space Center for Exploration Systems (PISCES) has aerospace research and education program for students, and a public monthly newsletter. (Image credits:)

TUESDAY

● Apr 8 — American Museum of Natural History, New York NY: Astronomy Live: Stellar Lifetimes; 19:00 EDT.

☾ Apr 8 — Moon: 1.96° NE of Regulus, 05:00.

☆ Apr 8 — Apollo Asteroid 2025 FF18: Near-Earth Flyby (0.022 AU)