🚀 Space Pulse · 2026-06-23 22:01 UTC
SPACE PULSE
Tuesday, 24 June 2026 | Edition 181
⚡ TL;DR
Webb has chemically fingerprinted interstellar comet 3I/ATLAS, revealing a surprising composition that challenges assumptions about our Solar System's uniqueness among planetary systems.
Three launches queue up in the next ten days, Artemis II crew imagery captivates the public, and a busy arXiv drop covers everything from Barnard's Star planets to Martian habitability.
🚀 LAUNCHES
STARLINK GROUP 17-46 — SpaceX Falcon 9 Block 5 carrying 24 Starlink satellites is go for launch on 2026-07-02 at 02:00 UTC. [1]
AMAZON LEO LA-08 — United Launch Alliance Atlas V 551 carrying a batch of Amazon Project Kuiper broadband constellation satellites is go for launch on 2026-07-02 at 04:24 UTC, just over two hours after the Starlink flight. [2]
STARLINK GROUP 10-50 — SpaceX Falcon 9 Block 5 carrying 29 Starlink satellites is go for launch on 2026-07-03 at 11:20 UTC, keeping the mega-constellation build-out at a relentless pace. [3]
NASA WALLOPS SOUNDING ROCKET — Wallops Flight Facility will support a suborbital sounding rocket for the Department of War during a window of June 26 through July 2, 2026; the vehicle may be visible from the Chesapeake Bay region. [4]
ROCKSAT-X / ROCKON STUDENT ROCKET — NASA Wallops plans to launch a sounding rocket carrying student-developed experiments from the RockSatX and RockOn programs on June 24, between 05:30 and 09:30 EDT, with a backup on June 25. [5]
🔭 DISCOVERIES
INTERSTELLAR COMET 3I/ATLAS CHEMICALLY DECODED — Webb captured detailed spectral measurements of comet 3I/ATLAS as it receded from the Sun in December 2025, revealing a composition that raises questions about how common or unusual our Solar System's conditions really are, per ESA and NASA. [6] [7]
WEBB RESOLVES MILLIONS OF STARS IN CIGAR GALAXY M82 — JWST has pinpointed individual stars inside Messier 82, located 12 million light-years away, an edge-on starburst galaxy whose intense star formation is thought to be triggered by a gravitational interaction, revealing previously unseen structural detail. [8] [9]
HUBBLE CATCHES EARLY GALAXY REIONIZING ITS NEIGHBORHOOD — Astronomers using HST detected ultraviolet light from a galaxy existing just 1.4 billion years after the Big Bang, showing that early galaxies actively transformed the intergalactic medium around them. [10]
CHANDRA FINDS POSSIBLE NEW SUPERNOVA REMNANT IN GALACTIC CENTER — X-ray data from NASA's Chandra Observatory, released June 11 and announced June 22, reveals what may be a supernova remnant in an intriguing neighborhood at the heart of the Milky Way, a source of key heavy elements like iron and oxygen.
🛰️ MISSIONS
ARTEMIS II CREW IMAGES HALF-ILLUMINATED MOON ON FLIGHT DAY 6 — The Artemis II crew photographed a striking half-lit Moon showing the terminator in sharp relief across its rocky, uneven near side, confirming the crew is actively conducting visual observations during the mission.
ISS EXPEDITION 74 PREPS FOR SPACEWALK 95 — The Expedition 74 crew spent the week beginning June 22 ramping up preparations for US Spacewalk 95, scheduled for June 30 at approximately 08:35 EDT, targeting replacement of a wrist joint on Canadarm2; NASA and CSA will host a preview news conference.
ISS CREW CONDUCTS BIOENGINEERING AND SPACE MANUFACTURING WORK — Alongside spacewalk prep, Expedition 74 conducted cartilage tissue bioengineering and advanced materials manufacturing experiments, plus vision tests, on June 22.
BOTSWANA TO SIGN ARTEMIS ACCORDS JUNE 25 — The Republic of Botswana will formally sign the Artemis Accords at NASA Headquarters at 09:30 EDT on June 25, hosted by NASA Deputy Administrator Matt Anderson; Botswana's Minister of Communications and Innovation David Tshere will attend.
XRISM SECOND INTERNATIONAL CONFERENCE ANNOUNCED — The XRISM project office has announced its 2nd International Conference, to be held June 1-4, 2027, in Detroit, Michigan, signaling the mission's growing scientific community.
☀️ SPACE WEATHER
ELEVATED ENERGETIC ELECTRON FLUX PERSISTING — NOAA SWPC issued continued ALTEF3 alerts (serial 3700 and 3701) on June 14-15 showing 2 MeV electron flux sustained above 1000 pfu since June 13 at 13:32 UTC, with a daily maximum reaching 1581 pfu on June 14; this level can charge-up satellites in geostationary orbit.
EARLIER JUNE ACTIVE PERIOD SUMMARY — An M9.3 flare (R2 Moderate) fired at 01:22 UTC June 3, followed by an M7.7 (R2) at 06:48 UTC and a strong X1.0 flare at 11:19 UTC the same day, which triggered an R3 Strong radio blackout and a G3 Strong geomagnetic storm watch for June 4-5.
G2-G3 STORM SEQUENCE EARLY JUNE — The June 3 X1.0 event drove a geomagnetic sudden impulse (70 nT deviation at station MEA) on June 5 at 05:11 UTC and sustained G1-G2 storm levels through June 6; a second G3 watch was issued June 6 for June 8-9 but was later cancelled as CME influence faded.
CURRENT CONDITIONS — The most recent alerts in the dataset date to mid-June; no fresh major storm warnings are present for the June 23 period, suggesting a relatively quieter interval following the active early-June sequence.
📄 RESEARCH
BARNARD'S STAR PLANETARY SYSTEM COMPOSITION STUDY — A new arXiv paper examines the four recently confirmed sub-Earth planets orbiting Barnard's Star, the nearest single star to the Sun at just 1.8 parsecs, using measured stellar abundances of Fe, Mg, and Si to constrain rock-forming composition and long-term orbital stability.
MARTIAN SHALLOW SUBSURFACE HABITABILITY QUANTIFIED — Researchers modeled the radiolytic habitable zone in Mars's shallow subsurface, where galactic cosmic rays may produce enough chemical energy to sustain life while UV light and surface oxidants are excluded; the paper spells out direct implications for the ExoMars Rosalind Franklin rover and China's Tianwen-3 mission.
XRISM MEASURES FE K-ALPHA REVERBERATION IN NGC 4151 — Using JAXA-NASA-ESA's XRISM observatory, a team detected time-lag echoes in the narrow iron K-alpha emission line of Seyfert-1.5 galaxy NGC 4151, using the signal as a probe of the geometry and distance to the central black hole's immediate environment.
JWST MIRI TRACES STELLAR WINDS OF O-TYPE STARS IN MID-INFRARED — A survey of 22 OB-type stars using JWST's MIRI instrument detects high-ionization fine-structure emission lines tracing stellar winds in four late O-dwarfs (O8 V to O9 V) and one early O-dwarf (O5 V), opening a new wavelength window on massive-star mass loss.
DARK AGES 21-CM SIGNAL AS PROBE OF PRIMORDIAL NON-GAUSSIANITY — A Fisher-forecast study shows that measuring the redshifted 21-cm power spectrum and bispectrum from the cosmic Dark Ages, while carefully accounting for the foreground contamination "wedge," could set tight constraints on primordial non-Gaussianity and thus discriminate between inflationary models.
HIP 41378 F TRANSIT OBSERVED — Astronomers caught the 2025 transit of HIP 41378 f, a giant planet with a 542-day orbital period showing large transit timing variations, adding new constraints on outer companions and demonstrating the rare opportunity that long-period transiting worlds provide for studying exomoon potential and primordial atmospheres.
📎 Sources
- Falcon 9 Block 5 | Starlink Group 17-46 — Launch Library 2
- Atlas V 551 | Amazon Leo (LA-08) — Launch Library 2
- Falcon 9 Block 5 | Starlink Group 10-50 — Launch Library 2
- NASA Wallops to Support Launch Beginning Late June — NASA Science
- NASA Sounding Rocket to Launch Student Experiments — NASA News Releases
- Webb finds clues to ancient origin of Comet 3I/ATLAS — ESA Top News
- NASA’s Webb Finds Clues to Ancient, Distant Origin of Comet 3I/ATLAS — NASA News Releases
- NASA’s Webb Pinpoints Millions of Stars Within Cigar Galaxy — NASA News Releases
- NASA’s Webb Pinpoints Millions of Stars Within Cigar Galaxy — NASA Science
- Hubble Details Early Galaxy Transforming Neighborhood — NASA News Releases
Curated from official sources — NASA/ESA/JAXA/ESO/NOAA/arXiv/Launch Library. Informational only.
Serial 20260623-22-v10 · 2026-06-23 22:01 UTC