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 in Tokyo, April 9-10 is held for researchers to discuss protecting Earth from asteroids, meteors and meteorites. The Tunguska Meteor, exploding June 30, 1908 had perhaps ~1,000 times Hiroshima energy and is now acknowledged yearly on that date as Asteroid Day. Chelyabinsk Meteor exploded in 2013, injuring ~1,500 and damaging ~7,200 buildings. The first Planetary Defense Conference (PDC) of the American Institute of Aeronautics and Astronautics was 2004, and that of International Academy of Astronautics (IAA) was 2009. IAA will host their 9th PDC in South Africa, May 5-9 this year. Co-convenor of the Tokyo workshop is Torino Scale inventor Richard Binzel, who 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-oriented missions ESA RAMSES, ExLabs ApophisExL, JAXA DESTINY+, Blue Origin Blue Ring, USRA Apophis Interceptor, Milo space Science Apophis Pathfinder, U of Maryland TERP RAPTOR and U of Arizona Apophis Precursor. A special session will foster dialogue between Chinese and international planetary scientists to enhance collaboration. (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; meanwhile are exercising while wearing breathing gear and electrodes, practicing with robotic flying devices ahead of a student competition, measuring radiation exposure with wearable dosimeters, testing new lower body negative pressure suits from Roscosmos with circulatory system sensors, checking fire safety gear, cleaning ventilation systems, adjusting oxygen sensors and transferring water between station tanks.

☆ Apr 7 — Tiangong Space Station, ~390-km LEO: Shenzhou 19 three-member crew working with planarians (flatworms) to see if segments regrow normally, continuing with zebrafish, planning for mice, achieving first cultivation of space-regenerated rice with completion of 120-day life cycle, seeing that fruit flies float and tumble instead of crawl or fly to complete courtship and mating activities, culturing muscle cells to see fusion and autophagy, growing semiconductor crystals that have significantly fewer density defects than Earth-grown.

☆ 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 — SpaceX, Launch Falcon 9 / Starlink Group 11-11, SLC-4E, Vandenberg SFB CA: Batch of satellites for Starlink mega-constellation space-based Internet communication system; launch window opens 11:35 PDT.

● 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: NASA, EHT, UH, et al)

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)

WEDNESDAY

★ Apr 9 — United Launch Alliance, Launch Atlas V 551 / Project Kuiper (KA-01), SLC-41, Cape Canaveral SFS FL: Internet satellites for Amazon subsidiary to LEO for constellation of 3,276; launch window 12:00-15:00 EDT.