Space science explorer and professor at Boston University. Space sensor builderhttps://bsky.app/profile/drbwalsh.bsky.socialhttps://bsky.app/profile/drbwalsh.bsky.social/post/3mfcaxz2yvc2hThe SMILE mission’s boat journey has begun - https://www.esa.int/Science_Exploration/Space_Science/Smile/Smile_sets_sail_for_Europe_s_Spaceport_in_French_Guiana (Interestingly, the boat ride distance ~7,500km is much further than the distance from Earth to low earth orbit ~400km) #heliophysics20 Feb 2026 13:52 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3mfcaxz2yvc2hhttps://bsky.app/profile/drbwalsh.bsky.social/post/3mbiikgdq2k2bHappy Periapsis Day to those that celebrate! Earth is at periapsis in its orbit around the sun. The closest point between Earth-sun in the year-long orbit.03 Jan 2026 03:43 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3mbiikgdq2k2bhttps://bsky.app/profile/drbwalsh.bsky.social/post/3mbgys6ffi22oGorgeous first-light images from Carruthers Observatory - absolutely amazing #heliophysics https://science.nasa.gov/science-research/heliophysics/nasas-carruthers-geocorona-observatory-reveals-first-light-images/02 Jan 2026 13:28 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3mbgys6ffi22ohttps://bsky.app/profile/drbwalsh.bsky.social/post/3m5fndcidwc2bGood views west of Boston tonight12 Nov 2025 02:50 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3m5fndcidwc2bhttps://bsky.app/profile/drbwalsh.bsky.social/post/3m2fxlzbil22fPower on! That small step function is the first power on in space of the COSSMo instrument from yesterday. The BU student-developed payload is on the Carruthers Geocoronal Observatory and will monitor the sun in UV and soft X-ray. #heliophysics05 Oct 2025 01:38 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3m2fxlzbil22fhttps://bsky.app/profile/drbwalsh.bsky.social/post/3lvsspavcas2nA small experiment - over the past 2 months I saved all the junk mail I received, ~7.1 lbs. Projecting to the number of adults in the US, that’s 813 million pounds of unsolicited mail every month in the US07 Aug 2025 13:09 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3lvsspavcas2nhttps://bsky.app/profile/drbwalsh.bsky.social/post/3lv44cxr7xs2cSMILE spacecraft passed through thermal testing. A nice video of the progress by the ESA team https://www.youtube.com/embed/8soC68zRNC8?rel=029 Jul 2025 12:30 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3lv44cxr7xs2chttps://bsky.app/profile/drbwalsh.bsky.social/post/3luptyxm2bk25This month marks 10 years teaching at @bostonu.bsky.social. It has been almost 1,000 energetic and curious Terrier students24 Jul 2025 15:29 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3luptyxm2bk25https://bsky.app/profile/drbwalsh.bsky.social/post/3lsmeqx7q7c22Motivating to be part of 450 US space scientists in Des Moines this week. My favorite line of the workshop “whether they know it or not, everyone in this country is becoming a space worker” in reference to the growing reliance of daily life on the space environment27 Jun 2025 19:28 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3lsmeqx7q7c22https://bsky.app/profile/drbwalsh.bsky.social/post/3licgf7bvvk2oLEXI made it to lunar orbit. 2 weeks to landing and X-ray imaging16 Feb 2025 14:18 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3licgf7bvvk2ohttps://bsky.app/profile/drbwalsh.bsky.social/post/3lgqdmavcbs2cOne of the most exciting step-functions in electrical current I’ve seen. Lexi powering up successfully shortly after reaching orbit. ☀️27 Jan 2025 16:16 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3lgqdmavcbs2chttps://bsky.app/profile/drbwalsh.bsky.social/post/3lfruhpuwic2rAnd we’re up15 Jan 2025 13:25 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3lfruhpuwic2rhttps://bsky.app/profile/drbwalsh.bsky.social/post/3lfqa6s4df22cT-8 hrs to launch. Weather in FL is looking good14 Jan 2025 21:49 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3lfqa6s4df22chttps://bsky.app/profile/drbwalsh.bsky.social/post/3lfp3zakshk2uT-less than a day to LEXI’s launch on the Blue Ghost. Weather in Florida is looking good14 Jan 2025 11:02 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3lfp3zakshk2uhttps://bsky.app/profile/drbwalsh.bsky.social/post/3lffcgk64ks27In 1651 if you wanted to bash someone’s idea you wrote a book with a gorgeous art critique. It looks like Riccioli didnt like geocentrism If there’s room you could also include one of the first maps of the moon defining many of the names we use today. Thanks to #bostonpubliclibrary for sharing10 Jan 2025 13:30 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3lffcgk64ks27https://bsky.app/profile/drbwalsh.bsky.social/post/3lf65cxw7yc2qT-8 days to LEXI's launch https://blogs.nasa.gov/artemis/2025/01/07/nasa-science-tech-launching-to-moon-in-mid-january/07 Jan 2025 17:10 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3lf65cxw7yc2qhttps://bsky.app/profile/drbwalsh.bsky.social/post/3lf3kdmxais2lQuickly approaching launch. Excitement is growing to image Earth's magnetosphere from space https://science.nasa.gov/science-research/heliophysics/nasas-lexi-will-provide-x-ray-vision-of-earths-magnetosphere/06 Jan 2025 16:25 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3lf3kdmxais2lhttps://bsky.app/profile/drbwalsh.bsky.social/post/3ldqsyqdemk2bde Magnete (1600) by Gilbert started magnetospheric physics. Earth is a magnet! When this was written this also resolved a debate of why compasses pointed north. Thanks to BPL Special Collections for sharing an original copy. #heliophysics20 Dec 2024 16:35 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3ldqsyqdemk2bhttps://bsky.app/profile/drbwalsh.bsky.social/post/3ld6vzuyzfs2eSMILE is on the move! Always impressive the logistics that go into shipping spacecraft https://youtu.be/7aJTuJPGYy8?feature=shared13 Dec 2024 13:42 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3ld6vzuyzfs2ehttps://bsky.app/profile/drbwalsh.bsky.social/post/3lbwusz2x6s2mTwo months out from launch! LEXI’s science mission ends when the sun and Earth are too close in the sky to image earths magnetic field without solar background. From LEXI and the moon, this is “new Earth.” From Earth’s perspective - a full moon. Graphic from @firefly-aerospace.bsky.social27 Nov 2024 15:34 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3lbwusz2x6s2mhttps://bsky.app/profile/drbwalsh.bsky.social/post/3layantimhx2tSMILE mission is coming together https://www.esa.int/ESA_Multimedia/Videos/2024/11/Introducing_the_Smile_mission_Let_s_Smile_episode_115 Nov 2024 11:13 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3layantimhx2thttps://bsky.app/profile/drbwalsh.bsky.social/post/3kmfj2dolsl2oBack to Helsinki with the Vlasiator team for more sabbatical numerical simulations. I’ve been told February is still the “dark” part of the year here27 Feb 2024 11:59 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3kmfj2dolsl2ohttps://bsky.app/profile/drbwalsh.bsky.social/post/3kffjjfiubz2cPrint(‘hello, world’)30 Nov 2023 10:11 +0000at://did:plc:n4o7gzsvqf4ervewcv447e75/app.bsky.feed.post/3kffjjfiubz2c