Daniel Apai
@danielapai.bsky.social
Professor of Astronomy, Planetary Sciences, and Optics at The University of Arizona. I study exoplanets, build telescopes, and lead the NASA-funded Alien Earths astrobiology team. Fellow of AAAS and The Explorers Club. Own opinions.
Countdown clock in @stewardobservatory.bsky.social for our NASA Pandora Space Telescope: T-60 days!!
Our team is getting ready for the launch of this incredibly exciting mission to explore worlds beyond the Solar System! #exoplanets @uazresearch.bsky.social @uarizonalpl.bsky.social
Our team is getting ready for the launch of this incredibly exciting mission to explore worlds beyond the Solar System! #exoplanets @uazresearch.bsky.social @uarizonalpl.bsky.social
November 6, 2025 at 5:01 AM
Countdown clock in @stewardobservatory.bsky.social for our NASA Pandora Space Telescope: T-60 days!!
Our team is getting ready for the launch of this incredibly exciting mission to explore worlds beyond the Solar System! #exoplanets @uazresearch.bsky.social @uarizonalpl.bsky.social
Our team is getting ready for the launch of this incredibly exciting mission to explore worlds beyond the Solar System! #exoplanets @uazresearch.bsky.social @uarizonalpl.bsky.social
I had fun talking about exoplanets and search for habitable worlds at The Explorers Club live event in Sedona. Sam Schwann, underwater explorer and artist followed with very cool videos of ocean exploration and swimming with sharks! Will do this again soon - next time in Tucson!
October 7, 2025 at 4:19 AM
I had fun talking about exoplanets and search for habitable worlds at The Explorers Club live event in Sedona. Sam Schwann, underwater explorer and artist followed with very cool videos of ocean exploration and swimming with sharks! Will do this again soon - next time in Tucson!
Enjoyed talking w Bruce Dorminey in Iceland about our universal framework to assess which exoplanets & moons may be habitable. Key for search for life beyond Earth! His story: @forbes.com
www.forbes.com/sites/bruced...
@stewardobservatory.bsky.social @uarizonalpl.bsky.social @uarizona.bsky.social
www.forbes.com/sites/bruced...
@stewardobservatory.bsky.social @uarizonalpl.bsky.social @uarizona.bsky.social
https://forbes.com/sites/brucedor…
August 22, 2025 at 3:53 AM
Enjoyed talking w Bruce Dorminey in Iceland about our universal framework to assess which exoplanets & moons may be habitable. Key for search for life beyond Earth! His story: @forbes.com
www.forbes.com/sites/bruced...
@stewardobservatory.bsky.social @uarizonalpl.bsky.social @uarizona.bsky.social
www.forbes.com/sites/bruced...
@stewardobservatory.bsky.social @uarizonalpl.bsky.social @uarizona.bsky.social
Much enjoyed last week's Sagan Summer School. Great to see friends, colleagues, & meet early-career scientists! My lecture and blog post on the future of exoplanet/sub-neptune research are now online:
www.youtube.com/watch?v=JSzY...
distantearths.com/sub-neptunes... @stewardobservatory.bsky.social
www.youtube.com/watch?v=JSzY...
distantearths.com/sub-neptunes... @stewardobservatory.bsky.social
July 30, 2025 at 3:51 PM
Much enjoyed last week's Sagan Summer School. Great to see friends, colleagues, & meet early-career scientists! My lecture and blog post on the future of exoplanet/sub-neptune research are now online:
www.youtube.com/watch?v=JSzY...
distantearths.com/sub-neptunes... @stewardobservatory.bsky.social
www.youtube.com/watch?v=JSzY...
distantearths.com/sub-neptunes... @stewardobservatory.bsky.social
Reposted by Daniel Apai
For 40 years, Michelle Cournoyer has supported students and faculty, solved problems, and shown up with heart. As she prepares to retire this August, we celebrate the impact of a true Steward Observatory legend: bit.ly/3GWkAQv
July 28, 2025 at 11:52 PM
For 40 years, Michelle Cournoyer has supported students and faculty, solved problems, and shown up with heart. As she prepares to retire this August, we celebrate the impact of a true Steward Observatory legend: bit.ly/3GWkAQv
Reposted by Daniel Apai
Exoplanet demographics are key: Integrative. A key point from today's talk by Daniel Apai at #sagan2025 on future prospects of key planetary processes and trends in the sub-Neptune population. #exoplanets
July 25, 2025 at 4:44 PM
Exoplanet demographics are key: Integrative. A key point from today's talk by Daniel Apai at #sagan2025 on future prospects of key planetary processes and trends in the sub-Neptune population. #exoplanets
Reposted by Daniel Apai
A new model helps scientists assess whether environments on alien worlds could support specific forms of life, real or hypothetical, based on known biological limits and uncertain data.
By @danielapai.bsky.social @uarizona.bsky.social:
buff.ly/M4VdDsu
By @danielapai.bsky.social @uarizona.bsky.social:
buff.ly/M4VdDsu
New model helps to figure out which distant planets may host life
As NASA rolls out more powerful telescopes in the future, scientists will need a way to determine where to point them. A new approach could help.
theconversation.com
June 4, 2025 at 3:48 AM
A new model helps scientists assess whether environments on alien worlds could support specific forms of life, real or hypothetical, based on known biological limits and uncertain data.
By @danielapai.bsky.social @uarizona.bsky.social:
buff.ly/M4VdDsu
By @danielapai.bsky.social @uarizona.bsky.social:
buff.ly/M4VdDsu
Reposted by Daniel Apai
When is an alien world habitable? Steward Observatory's @danielapai.bsky.social explores this question in his latest article in The Conversation: bit.ly/43vZKQw
June 3, 2025 at 10:52 PM
When is an alien world habitable? Steward Observatory's @danielapai.bsky.social explores this question in his latest article in The Conversation: bit.ly/43vZKQw
Reposted by Daniel Apai
With all the buzz about the latest potential sign of life on a distant planet, Steward Observatory's astronomy professor @danielapai.bsky.social puts the discovery in context. Read his take: bit.ly/3S1fYKB
April 23, 2025 at 12:26 AM
With all the buzz about the latest potential sign of life on a distant planet, Steward Observatory's astronomy professor @danielapai.bsky.social puts the discovery in context. Read his take: bit.ly/3S1fYKB
Reposted by Daniel Apai
While we're on the topic of biosignatures, I'd like to re-up my last two papers about the challenges of observing O₂ (a key biosignature) on 𝘌𝘢𝘳𝘵𝘩-𝘭𝘪𝘬𝘦 exoplanets with the biggest upcoming optical/IR telescopes ever built:
ui.adsabs.harvard.edu/abs/2025AJ.....
ui.adsabs.harvard.edu/abs/2023AJ.....
ui.adsabs.harvard.edu/abs/2025AJ.....
ui.adsabs.harvard.edu/abs/2023AJ.....
Bioverse: Giant Magellan Telescope and Extremely Large Telescope Direct Imaging and High-resolution Spectroscopy Assessment—Surveying Exo-Earth O<SUB>2</SUB> and Testing the Habitable Zone Oxygen Hypo...
Biosignature detection in the atmospheres of Earth-like exoplanets is one of the most significant and ambitious goals for astronomy, astrobiology, and humanity. Molecular oxygen is among the strongest...
ui.adsabs.harvard.edu
April 18, 2025 at 3:23 AM
While we're on the topic of biosignatures, I'd like to re-up my last two papers about the challenges of observing O₂ (a key biosignature) on 𝘌𝘢𝘳𝘵𝘩-𝘭𝘪𝘬𝘦 exoplanets with the biggest upcoming optical/IR telescopes ever built:
ui.adsabs.harvard.edu/abs/2025AJ.....
ui.adsabs.harvard.edu/abs/2023AJ.....
ui.adsabs.harvard.edu/abs/2025AJ.....
ui.adsabs.harvard.edu/abs/2023AJ.....
Exciting nights! We are integrating the first prototype telescope based on Nautilus multi-order diffractive optics! At Mt Lemmon Sky Center. Our telescope is unique, custom-built to demonstrate broadband imaging with a light, flat lens! @stewardobservatory.bsky.social @uarizona.bsky.social
April 12, 2025 at 3:52 AM
Exciting nights! We are integrating the first prototype telescope based on Nautilus multi-order diffractive optics! At Mt Lemmon Sky Center. Our telescope is unique, custom-built to demonstrate broadband imaging with a light, flat lens! @stewardobservatory.bsky.social @uarizona.bsky.social
Reposted by Daniel Apai
Here is a great postdoc opportunity at LPL with Sukrit Ranjan to study photochemistry and atmospheric escape for terrestrial planets. arizona.csod.com/ux/ats/caree...
Postdoctoral Research Associate I (Lunar and Planetary Laboratory)
The successful applicant will conduct original research in collaboration with Prof. Sukrit
Ranjan and his group related to the composition and structu...
arizona.csod.com
April 5, 2025 at 2:57 PM
Here is a great postdoc opportunity at LPL with Sukrit Ranjan to study photochemistry and atmospheric escape for terrestrial planets. arizona.csod.com/ux/ats/caree...
Reposted by Daniel Apai
PUBLISHED!!! Go check out IF we will be able to look for a key biosignature (oxygen!) with the Giant Magellan Telescope and the Extremely Large Telescope!
🔭🪐🧪
iopscience.iop.org/article/10.3...
🔭🪐🧪
iopscience.iop.org/article/10.3...
February 27, 2025 at 12:31 AM
PUBLISHED!!! Go check out IF we will be able to look for a key biosignature (oxygen!) with the Giant Magellan Telescope and the Extremely Large Telescope!
🔭🪐🧪
iopscience.iop.org/article/10.3...
🔭🪐🧪
iopscience.iop.org/article/10.3...
Reposted by Daniel Apai
The Art of Planetary Science is in full swing at @uarizonalpl.bsky.social Come visit this weekend!
February 22, 2025 at 1:31 AM
The Art of Planetary Science is in full swing at @uarizonalpl.bsky.social Come visit this weekend!
Reposted by Daniel Apai
Happy to announce we have joined BlueSky and look forward to sharing information about the amazing discoveries we make at CSS. Stick around for some neat stuff! #astronomy #asteroids #planetarydefense
February 13, 2025 at 10:56 PM
Happy to announce we have joined BlueSky and look forward to sharing information about the amazing discoveries we make at CSS. Stick around for some neat stuff! #astronomy #asteroids #planetarydefense
Reposted by Daniel Apai
Glen Schneider (1955–2025) was a self-confessed "umbraphile" -- a "shadow-lover" who pursued solar eclipses around the globe and earned a world record for the greatest number of total solar eclipses ever experienced. Read about his work and lasting legacy: bit.ly/4hVUaet
February 13, 2025 at 7:51 PM
Glen Schneider (1955–2025) was a self-confessed "umbraphile" -- a "shadow-lover" who pursued solar eclipses around the globe and earned a world record for the greatest number of total solar eclipses ever experienced. Read about his work and lasting legacy: bit.ly/4hVUaet
Glenn was an exceptional scholar and kind colleague whose office door was always open. His debris disk images will continue to inspire. As a dedicated solar eclipse chaser, he captured the rare ethereal beauty of science around the globe. Ad Astra, Glenn! nicmosis.as.arizona.edu:8000/UMBRAPHILLIA...
February 6, 2025 at 11:30 PM
Glenn was an exceptional scholar and kind colleague whose office door was always open. His debris disk images will continue to inspire. As a dedicated solar eclipse chaser, he captured the rare ethereal beauty of science around the globe. Ad Astra, Glenn! nicmosis.as.arizona.edu:8000/UMBRAPHILLIA...
I am thrilled to speak in the College of Science Lecture Series "Can We Talk?". On March 27, Chris Impey and I will explore a really cool topic: communicating with alien civilizations!
science.arizona.edu/community-en...
@stewardobservatory.bsky.social @uarizona.bsky.social @uarizonalpl.bsky.social
science.arizona.edu/community-en...
@stewardobservatory.bsky.social @uarizona.bsky.social @uarizonalpl.bsky.social
February 2, 2025 at 4:27 AM
I am thrilled to speak in the College of Science Lecture Series "Can We Talk?". On March 27, Chris Impey and I will explore a really cool topic: communicating with alien civilizations!
science.arizona.edu/community-en...
@stewardobservatory.bsky.social @uarizona.bsky.social @uarizonalpl.bsky.social
science.arizona.edu/community-en...
@stewardobservatory.bsky.social @uarizona.bsky.social @uarizonalpl.bsky.social
Excellent study of a very exciting substellar companion in the Pleiades!
I'm very excited to share that my first (and first-author) publication is up on the arXiv today!
arxiv.org/abs/2501.16429
We studied a circumbinary brown dwarf companion in the Pleiades with direct imaging taken using both apertures of the Large Bincocular Telescope.
arxiv.org/abs/2501.16429
We studied a circumbinary brown dwarf companion in the Pleiades with direct imaging taken using both apertures of the Large Bincocular Telescope.
January 31, 2025 at 4:51 AM
Excellent study of a very exciting substellar companion in the Pleiades!
Reposted by Daniel Apai
Unlike in 2024 I won't be offering a topic this year but this is really a unique program for students in astrophysics, software engineering, instrument calibration/support, and public outreach/scientific writing.
Check out the SASP @spacetelescope.bsky.social & apply!
www.stsci.edu/opportunitie...
Check out the SASP @spacetelescope.bsky.social & apply!
www.stsci.edu/opportunitie...
Space Astronomy Summer Program
Fostering hands-on astronomy, engineering, and public outreach project opportunities to serve upper-division undergraduate students.
www.stsci.edu
January 3, 2025 at 8:21 PM
Unlike in 2024 I won't be offering a topic this year but this is really a unique program for students in astrophysics, software engineering, instrument calibration/support, and public outreach/scientific writing.
Check out the SASP @spacetelescope.bsky.social & apply!
www.stsci.edu/opportunitie...
Check out the SASP @spacetelescope.bsky.social & apply!
www.stsci.edu/opportunitie...
A great visit to White Sands National Park. We enjoyed a hike deep into the dune fields. Amazing wind-sculpted landscape! Pretty cool that the gypsum ultimately originates from layers deposited by the Permian Sea on the Pangea supercontinent about 250 million years ago!
December 30, 2024 at 1:30 AM
A great visit to White Sands National Park. We enjoyed a hike deep into the dune fields. Amazing wind-sculpted landscape! Pretty cool that the gypsum ultimately originates from layers deposited by the Permian Sea on the Pangea supercontinent about 250 million years ago!
Reposted by Daniel Apai
Have questions to NASA Astrophysics Division Director and about Program Analysis Groups? Attend the Joint PAG Session at the AAS on January 12. More info here: cor.gsfc.nasa.gov/copag/meetin...
Cosmic Origins (COR)
Web site for the NASA Cosmic Origins Program
cor.gsfc.nasa.gov
December 11, 2024 at 3:41 PM
Have questions to NASA Astrophysics Division Director and about Program Analysis Groups? Attend the Joint PAG Session at the AAS on January 12. More info here: cor.gsfc.nasa.gov/copag/meetin...
Our exoplanets and astrobiology research group – what a thrill to work with this amazing team on exploring new worlds! @gabeweible.bsky.social @stewardobservatory.bsky.social @bemiles.bsky.social @sailorsupernova.bsky.social @matthewmurphy.bsky.social @kevinkhu.bsky.social
December 10, 2024 at 4:28 AM
Our exoplanets and astrobiology research group – what a thrill to work with this amazing team on exploring new worlds! @gabeweible.bsky.social @stewardobservatory.bsky.social @bemiles.bsky.social @sailorsupernova.bsky.social @matthewmurphy.bsky.social @kevinkhu.bsky.social
Reposted by Daniel Apai
An Impact in Elysium Planitia
This image shows an impact crater in Elysium Planitia that was first discovered by the Mars Context Camera that formed between February 2012 and June 2014.
More: uahirise.org/hipod/ESP_03...
NASA/JPL-Caltech/University of Arizona
#Mars #science #NASA
This image shows an impact crater in Elysium Planitia that was first discovered by the Mars Context Camera that formed between February 2012 and June 2014.
More: uahirise.org/hipod/ESP_03...
NASA/JPL-Caltech/University of Arizona
#Mars #science #NASA
November 30, 2024 at 1:23 PM
An Impact in Elysium Planitia
This image shows an impact crater in Elysium Planitia that was first discovered by the Mars Context Camera that formed between February 2012 and June 2014.
More: uahirise.org/hipod/ESP_03...
NASA/JPL-Caltech/University of Arizona
#Mars #science #NASA
This image shows an impact crater in Elysium Planitia that was first discovered by the Mars Context Camera that formed between February 2012 and June 2014.
More: uahirise.org/hipod/ESP_03...
NASA/JPL-Caltech/University of Arizona
#Mars #science #NASA
Reposted by Daniel Apai
Exploring Tucson? The New York Times recommends heading to the Mt. Lemmon SkyCenter, where scientists lead "staggering viewings through giant telescopes." Be sure to book your viewing! skycenter.arizona.edu/news/nyt-spe...
The NYT Spends 36 Hours in Tucson - Including the Mt. Lemmon SkyCenter
skycenter.arizona.edu
November 21, 2024 at 10:59 PM
Exploring Tucson? The New York Times recommends heading to the Mt. Lemmon SkyCenter, where scientists lead "staggering viewings through giant telescopes." Be sure to book your viewing! skycenter.arizona.edu/news/nyt-spe...