Episode 424 - Hunting for atmospheres on other planets

Mars was once covered with water, so where did all the water on Mars go? What happened to the water in the Martian atmosphere? Why isn't there an abundance of heavy water in the Martian atmosphere? Water can get trapped inside rocks and minerals without volcanoes to cycle them. Volcanoes and tectonics help sequester, cycle and release water, so what happens on a planet without them? How can we hunt for signs of water atmospheres on exoplanets? On hot rocky exoplanets with oceans of magma, what happens to their hydrogen rich atmospheres?  An atmosphere of of hydrogen can slowly turn and change into water with the help of a magma ocean. 
References:

1. E. L. Scheller, B. L. Ehlmann, Renyu Hu, D. J. Adams, Y. L. Yung. Long-term drying of Mars by sequestration of ocean-scale volumes of water in the crust. Science, 2021; eabc7717 DOI: 10.1126/science.abc7717
2. Edwin S. Kite, Laura Schaefer. Water on Hot Rocky Exoplanets. The Astrophysical Journal Letters, 2021; 909 (2): L22 DOI: 10.3847/2041-8213/abe7dc

Episode 419 - Testing life on Mars here on Earth

Perseverance has landed and begun it's long mission, but how can scientists on Earth help research on Mars? Can we study life on Mars here on Earth? Robotic missions aren't the only way Martian rock has made it's way to Earth. Rare meteorites from Mars can be used to test how life would grow in Martian soil. Just how old is the Jezero crater? Can you date a crater without doing detailed tests? How does measuring lunar craters help us put a date on the age of Martian craters like Jezero?

1. T. Milojevic, M. Albu, D. Kölbl, G. Kothleitner, R. Bruner, M. Morgan. Chemolithotrophy on the Noachian Martian breccia NWA 7034 via experimental microbial biotransformation. Communications Earth & Environment, 2021 DOI: 10.1038/s43247-021-00105-x
2. Cassata, W. S., Cohen, B. E., Mark, D. F., Trappitsch, R., Crow, C. A., Wimpenny, J., . . . Smith, C. L. (2018). Chronology of martian breccia nwa 7034 and the formation of the martian crustal dichotomy. Science Advances, 4(5). doi:10.1126/sciadv.aap8306
3. Simone Marchi. A new martian crater chronology: Implications for Jezero crater. The Astronomical Journal, 2021 [abstract]

Episode 414 - The active life and dramatic death of galaxies

Can a galaxy really die? What would that even look like? We know that stars can erupt into supernova, form black holes or fade away but what happens to old galaxies? What happens to a galaxy when it looses all it's fuel for growing new stars? Which galaxies are the most active and pulsing with light? Active galaxies often shine vibrantly from their core, but what causes periodic bursts of energy. NASA Goddarrd researchers have discovered the 'Old Faithful' of Galaxies.

1. Annagrazia Puglisi, Emanuele Daddi, Marcella Brusa, Frederic Bournaud, Jeremy Fensch, Daizhong Liu, Ivan Delvecchio, Antonello Calabrò, Chiara Circosta, Francesco Valentino, Michele Perna, Shuowen Jin, Andrea Enia, Chiara Mancini, Giulia Rodighiero. A titanic interstellar medium ejection from a massive starburst galaxy at redshift 1.4. Nature Astronomy, 2021; DOI: 10.1038/s41550-020-01268-x
2. ASA/Goddard Space Flight Center. (2021, January 12). An 'old faithful' active galaxy: Black hole rips away at star. ScienceDaily. Retrieved January 15, 2021 from www.sciencedaily.com/releases/2021/01/210112125154.htm

Episode 405 - Studying Supernova, pollution and air quality with trees

Studying supernova and air quality with the help of trees. Supernova are some of the most devastating events in the universe, but what is their connection to trees? By studying tree rings we can help piece together the final days of stars. Supernova can cause large spikes in radiation that can be detected in tree rings. Trees do a lot for us but they can also help us track air quality simply and cheaply. Magnets and pine needles can helps us understand air quality. Air quality monitoring can be a matter of running a magnet over some leaves.

References:

1. G. Robert Brakenridge. Solar system exposure to supernova γ radiation. International Journal of Astrobiology, 2020; 1 DOI: 10.1017/S1473550420000348
2. Grant Rea‐Downing, Brendon J. Quirk, Courtney L. Wagner, Peter C. Lippert. Evergreen needle magnetization as a proxy for particulate matter pollution in urban environments. GeoHealth, 2020; DOI: 10.1029/2020GH000286

Episode 401 - Space Collisions and cleaning up debris

Dodging collisions faster than a speeding bullet. We look at cleaning up space debris. Explosions and collisions of spaceships is great in sci-fi but bad news for us on Earth. Space is rapidly filling with satellites. What happens to them at the end of their life? Collisions in space (or near misses) are becoming more and more common. How can we clean up space and keep the skies safe for important satellites.
References

1. Crane, L. (n.d.). Two old spacecraft just avoided catastrophically colliding in orbit. Retrieved October 17, 2020, from https://www.newscientist.com/article/2257525-two-old-spacecraft-just-avoided-catastrophically-colliding-in-orbit/
2. Davenport, C. (2020, October 16). A rocket booster and a dead satellite avoided a collision Thursday, illustrating the 'ticking time bomb' of space debris. Retrieved October 17, 2020, from https://www.washingtonpost.com/technology/2020/10/15/space-collision-might-happen-thursday/
3. Marks, P. (2017, April 18). Satellite swarms could increase space junk risk by 50 per cent. Retrieved October 17, 2020, from https://www.newscientist.com/article/2128024-satellite-swarms-could-increase-space-junk-risk-by-50-per-cent/
4. Wall, M. (2019, April 24). Meet OSCaR: Tiny Cubesat Would Clean Up Space Junk. Retrieved October 17, 2020, from https://www.space.com/space-junk-cleanup-cubesat-oscar.html
5. Wall, M. (2020, June 23). Foam 'spider webs' from tiny satellites could help clean up space junk. Retrieved October 17, 2020, from https://www.space.com/space-junk-cleanup-foam-satellite-technology.html
6. Wells, T. (2019, April 24). Rensselaer team developing tool to battle space debris. Retrieved October 17, 2020, from https://phys.org/news/2019-04-rensselaer-team-tool-space-debris.html

Episode 394 - Travelling through time with telescopes

Telescopes can help us travel back in time to the early universe. We can watch galaxies form, the universe have a makeover and giant black holes appear. Using different telescopes we can learn about the cosmic dawn and the cosmic noon. The early universe was hazy and hard for light to travel far. What gave the early universe a makeover to allow starlight to travel? What fed the super hungry super massive black-holes of the early universe? Where did the early black holes find enough food to make them swell to massive sizes? What can we learn from the cosmic noon when most of the stars in the universe were formed? 

1. NASA/Goddard Space Flight Center. (2020, January 6). Astronomers spot distant galaxy group driving ancient cosmic makeover. ScienceDaily. Retrieved January 11, 2020 from www.sciencedaily.com/releases/2020/01/200106141610.htm
2. Emanuele Paolo Farina, Fabrizio Arrigoni-Battaia, Tiago Costa, Fabian Walter, Joseph F. Hennawi, Alyssa B. Drake, Roberto Decarli, Thales A. Gutcke, Chiara Mazzucchelli, Marcel Neeleman, Iskren Georgiev, Anna-Christina Eilers, Frederick B. Davies, Eduardo Bañados, Xiaohui Fan, Masafusa Onoue, Jan-Torge Schindler, Bram P. Venemans, Feige Wang, Jinyi Yang, Sebastian Rabien, Lorenzo Busoni. The REQUIEM Survey. I. A Search for Extended Lyα Nebular Emission Around 31 z > 5.7 Quasars. The Astrophysical Journal, 2019; 887 (2): 196 DOI: 10.3847/1538-4357/ab5847
3. T. Mauch et al. The 1.28 GHz MeerKAT DEEP2 Image. The Astrophysical Journal, 2019 [link]

Episode 391 - Mysteries of the sun, stellar weather and magnetic fields

The sun contains many mysteries, which are hard to unravel without special space probes. Why is the sun's corona so much hotter than the sun's surface? What helps form the biggest solar flares? When two arches of the sun's magnetic fields meet it can create some dangerous flares. Solar storms and solar flares can destroy satellites, power grids and spaceships. How can we better predict stellar weather and avoid disaster? Mapping out the Suns magnetic field can help us better predict stellar weather.

1. European Space Agency. (2020, July 16). Solar Orbiter's first images reveal 'campfires' on the Sun: ESA/NASA mission returns first data, snaps closest pictures of the Sun. ScienceDaily. Retrieved August 7, 2020 from www.sciencedaily.com/releases/2020/07/200716120652.htm
2. Kanya Kusano, Tomoya Iju, Yumi Bamba, Satoshi Inoue. A physics-based method that can predict imminent large solar flares. Science, 2020; 369 (6503): 587 DOI: 10.1126/science.aaz2511

Episode 387 - Black holes dancing, colliding and third wheeling

Scientists have discovered the closet black hole to Earth, but relax it's 1000 Light years away. Ever felt like a third wheel, just be thankful it's not a black hole. A binary star system that can be seen with the naked eye with a lurking black hole. Super massive  black holes are hard to get your head around but can unleash tremendous energy. When two super massive black holes dance around each other, the fireworks are spectacular. Predicting when two black holes will graze past each other helps us refine our understanding of the universe.

1. Th. Rivinius, D. Baade, P. Hadrava, M. Heida and R. Klement. A naked-eye triple system with a nonaccreting black hole in the inner binary. Astronomy & Astrophysics, 2020 DOI: 10.1051/0004-6361/202038020
2. Seppo Laine, Lankeswar Dey, Mauri Valtonen, A. Gopakumar, Stanislaw Zola, S. Komossa, Mark Kidger, Pauli Pihajoki, José L. Gómez, Daniel Caton, Stefano Ciprini, Marek Drozdz, Kosmas Gazeas, Vira Godunova, Shirin Haque, Felix Hildebrandt, Rene Hudec, Helen Jermak, Albert K. H. Kong, Harry Lehto, Alexios Liakos, Katsura Matsumoto, Markus Mugrauer, Tapio Pursimo, Daniel E. Reichart, Andrii Simon, Michal Siwak, Eda Sonbas. Spitzer Observations of the Predicted Eddington Flare from Blazar OJ 287. The Astrophysical Journal, 2020; 894 (1): L1 DOI: 10.3847/2041-8213/ab79a4

Episode 383 - Pulsars and fast radio bursts

From pulsars to fast radio bursts, we look at interstellar mysteries. Just how do Pulsars work? How long does it take for a Pulsar to be fed by surrounding matter? All that accretion disk matter spillaring around a Pulsar takes a long time to get there. What are Fast Radio Bursts? mysterious signals from deep space, or wobbly highly magnetised neutron stars? Magnetars, fast radio bursts and flares. What causes a fast radio burst in space to repeat?

1. D R Lorimer, E F Keane, A Karastergiou, M Caleb, R P Breton, C G Bassa, D Agarwal, V Morello, B W Stappers, M B Mickaliger, K M Rajwade. Possible periodic activity in the repeating FRB 121102. Monthly Notices of the Royal Astronomical Society, 2020; 495 (4): 3551 DOI: 10.1093/mnras/staa1237
2. Brian D Metzger, Ben Margalit, Lorenzo Sironi, Fast radio bursts as synchrotron maser emission from decelerating relativistic blast waves, Monthly Notices of the Royal Astronomical Society, Volume 485, Issue 3, May 2019, Pages 4091–4106, https://doi.org/10.1093/mnras/stz700
3. Hall, S., & Quanta Magazine. (n.d.). A Surprise Discovery Points to the Source of Fast Radio Bursts. Retrieved June 13, 2020, from https://www.quantamagazine.org/a-surprise-discovery-shows-magnetars-create-fast-radio-bursts-20200611/
4. Monash University. (2020, June 3). Astronomers capture a pulsar 'powering up'. ScienceDaily. Retrieved June 13, 2020 from www.sciencedaily.com/releases/2020/06/200603104549.htm
5. A. J. Goodwin and D. M. Russell and D. K. Galloway et al, A 12 day delay between optical and X-ray activity during outburst rise in a low-mass X-ray binary, arXiv, astro-ph.HE, 2006.02872, 2020

Episode 380 - New comets, touching an asteroid and the moon

New comets, touching down on an asteroid and fake diamonds on the moon. Small objects in our solar system can teach us about the early days of Earth. What happened on the moon 4.5 billion years ago to form cubic zirconia on the surface? What can we learn about the moon 4. billion years ago  in dust brought back by Apollo 17? A new comet is appears for the end of May which you can see near sunrise. Another comet discovered by Michael Mattiazzo can be see near sunrise at the end of May. Touching down on an asteroid is an incredible feat, and the preliminary data from Hyabusa2 and Ryugu are fascinating.

1. T. Morota, S. Sugita, Y. Cho, M. Kanamaru, E. Tatsumi, N. Sakatani, R. Honda, N. Hirata, H. Kikuchi, M. Yamada, Y. Yokota, S. Kameda, M. Matsuoka, H. Sawada, C. Honda, T. Kouyama, K. Ogawa, H. Suzuki, K. Yoshioka, M. Hayakawa, N. Hirata, M. Hirabayashi, H. Miyamoto, T. Michikami, T. Hiroi, R. Hemmi, O. S. Barnouin, C. M. Ernst, K. Kitazato, T. Nakamura, L. Riu, H. Senshu, H. Kobayashi, S. Sasaki, G. Komatsu, N. Tanabe, Y. Fujii, T. Irie, M. Suemitsu, N. Takaki, C. Sugimoto, K. Yumoto, M. Ishida, H. Kato, K. Moroi, D. Domingue, P. Michel, C. Pilorget, T. Iwata, M. Abe, M. Ohtake, Y. Nakauchi, K. Tsumura, H. Yabuta, Y. Ishihara, R. Noguchi, K. Matsumoto, A. Miura, N. Namiki, S. Tachibana, M. Arakawa, H. Ikeda, K. Wada, T. Mizuno, C. Hirose, S. Hosoda, O. Mori, T. Shimada, S. Soldini, R. Tsukizaki, H. Yano, M. Ozaki, H. Takeuchi, Y. Yamamoto, T. Okada, Y. Shimaki, K. Shirai, Y. Iijima, H. Noda, S. Kikuchi, T. Yamaguchi, N. Ogawa, G. Ono, Y. Mimasu, K. Yoshikawa, T. Takahashi, Y. Takei, A. Fujii, S. Nakazawa, F. Terui, S. Tanaka, M. Yoshikawa, T. Saiki, S. Watanabe, Y. Tsuda. Sample collection from asteroid (162173) Ryugu by Hayabusa2: Implications for surface evolution. Science, 2020; 368 (6491): 654 DOI: 10.1126/science.aaz6306
2. NASA/Goddard Space Flight Center. (2020, May 13). New comet discovered by solar observatory. ScienceDaily. Retrieved May 23, 2020 from www.sciencedaily.com/releases/2020/05/200513135517.htm
3. L. F. White, A. Černok, J. R. Darling, M. J. Whitehouse, K. H. Joy, C. Cayron, J. Dunlop, K. T. Tait, M. Anand. Evidence of extensive lunar crust formation in impact melt sheets 4,330 Myr ago. Nature Astronomy, 2020; DOI: 10.1038/s41550-020-1092-5

Episode 377 - Hubble turns 30 and still takes amazing images

We celebrate the life and achievements of Hubble Space telescope and all that have worked on it over it's 30 years in space (and many more before that). We look at the challenges faced by Hubble early on, and the amazing science it is helping contribute to today. From stars being born, to comets tearing themselves apart Hubble sheds light on amazing science. The images Hubble takes are iconic and often look like science fiction. Hubble manages to celebrate it's birthday by capturing images of a comet tearing itself apart.

1. Information@eso.org. (n.d.). Hubble Celebrates its 30th Anniversary with a Tapestry of Blazing Starbirth. Retrieved May 02, 2020, from https://www.spacetelescope.org/news/heic2007/
2. ESA/Hubble Information Centre. (2020, April 28). Hubble captures breakup of comet ATLAS. ScienceDaily. Retrieved May 1, 2020 from www.sciencedaily.com/releases/2020/04/200428142410.htm

Episode 370 - Explosions in space and citizen science

From galactic explosions, and waiting for supernova space is full of mysteries. What happens when a super massive black hole in a massive galaxy cluster...erupts? A massive explosion shred a hole 15 times larger than the Milky Way. What is happening with Betelgeuse? Could Betelgeuse just have shed it's coat? Is Betelgeuse about to go 'nova or is something else happening?   We find out about galactic research you can do from your couch. Tracing out a spiral is easy for humans to do, so why not help trace out a galaxy? Looking for something to do at home, why not citizen science helping trace galaxies?
References:

1. S. Giacintucci, M. Markevitch, M. Johnston-Hollitt, D. R. Wik, Q. H. S. Wang, T. E. Clarke. Discovery of a giant radio fossil in the Ophiuchus galaxy cluster. The Astrophysical Journal, 2020 [link]
2. Patrick Treuthardt, Ian B Hewitt. Comparison of galaxy spiral arm pitch angle measurements using manual and automated techniques. Monthly Notices of the Royal Astronomical Society, 2020; 493 (3): 3854 DOI: 10.1093/mnras/staa354
3. Emily M. Levesque, Philip Massey. Betelgeuse Just Isn't That Cool: Effective Temperature Alone Cannot Explain the Recent Dimming of Betelgeuse. submitted to arXiv, 2020 [link]

Episode 366 - The YORP Effect, Star Brawls and Solar wind

What happens when stars brawl? What do they leave behind? When stars are dying they take down everything and everything around them from asteroids to other stars. What is the YORP effect? How do some tiny solar particles destroy an asteroid? Spiraling out of control, asteroids get YORP-ed at the end of a star's life. When a star gets to the end of it's life, it may swell in size, taking out asteroids and nearby stars.

1. H. Olofsson, T. Khouri, M. Maercker, P. Bergman, L. Doan, D. Tafoya, W. H. T. Vlemmings, E. M. L. Humphreys, M. Lindqvist, L. Nyman, S. Ramstedt. HD 101584: circumstellar characteristics and evolutionary status. Astronomy & Astrophysics, 2019; 623: A153 DOI: 10.1051/0004-6361/201834897
2. Dimitri Veras, Daniel J Scheeres. Post-main-sequence debris from rotation-induced YORP break-up of small bodies – II. Multiple fissions, internal strengths, and binary production. Monthly Notices of the Royal Astronomical Society, 2020; 492 (2): 2437 DOI: 10.1093/mnras/stz3565
3. M. I. Desai, D. G. Mitchell, J. R. Szalay, E. C. Roelof, J. Giacalone, M. E. Hill, D. J. McComas, E. R. Christian, N. A. Schwadron, R. L. McNutt Jr., M. E. Wiedenbeck, C. Joyce, C. M. S. Cohen, R. W. Ebert, M. A. Dayeh, R. C. Allen, A. J. Davis, S. M. Krimigis, R. A. Leske, W. H. Matthaeus, O. Malandraki, R. A. Mewaldt, A. Labrador, E. C. Stone, S. D. Bale, M. Pulupa, R. J. MacDowall, J. C. Kasper. Properties of Suprathermal-through-energetic He Ions Associated with Stream Interaction Regions Observed over the Parker Solar Probe’s First Two Orbits. The Astrophysical Journal Supplement Series, 2020; 246 (2): 56 DOI: 10.3847/1538-4365/ab65ef

Episode 361 - Fast Radio Bursts, Cosmic Rays and Antarctica

From Fast Radio Bursts to Cosmic rays, interstellar mystery solving is a team effort. Mysterious repeating signals from space are tricky to localize, like spotting a person on the moon from here on Earth. What can fast radio bursts from billions of light years away tell us about the nature of the universe? How do you hunt for the source of a mysterious radio burst billions of light years away? How does a tiger, a balloon and Antarctica help us understand Supernova? What's the best place to hunt for cosmic rays; floating above Antarctica with a Super Tiger.

1. B. Marcote, K. Nimmo, J. W. T. Hessels, S. P. Tendulkar, C. G. Bassa, Z. Paragi, A. Keimpema, M. Bhardwaj, R. Karuppusamy, V. M. Kaspi, C. J. Law, D. Michilli, K. Aggarwal, B. Andersen, A. M. Archibald, K. Bandura, G. C. Bower, P. J. Boyle, C. Brar, S. Burke-Spolaor, B. J. Butler, T. Cassanelli, P. Chawla, P. Demorest, M. Dobbs, E. Fonseca, U. Giri, D. C. Good, K. Gourdji, A. Josephy, A. Yu. Kirichenko, F. Kirsten, T. L. Landecker, D. Lang, T. J. W. Lazio, D. Z. Li, H.-H. Lin, J. D. Linford, K. Masui, J. Mena-Parra, A. Naidu, C. Ng, C. Patel, U.-L. Pen, Z. Pleunis, M. Rafiei-Ravandi, M. Rahman, A. Renard, P. Scholz, S. R. Siegel, K. M. Smith, I. H. Stairs, K. Vanderlinde, A. V. Zwaniga. A repeating fast radio burst source localized to a nearby spiral galaxy. Nature, 2020; DOI: 10.1038/s41586-019-1866-z
2. Ogliore, T. (2020, January 10). SuperTIGER on its second prowl -- 130,000 feet above Antarctica: The Source: Washington University in St. Louis. Retrieved from https://source.wustl.edu/2020/01/supertiger-on-its-second-prowl-130000-feet-above-antarctica/.

Episode 359 - Life surviving on freezing planets, faint suns and meteorites

What can bacteria from an iron ore rich lake tell us about life on early earth? Have scientists finally solved a Carl Sagan paradox about life on early earth? When the earth was young, so was the sun, and that meant less light and heat. How did early life on earth survive if there was not enough sunlight to keep it warm? How did iron ore eating and secreting bacteria help lead to widespread life on our planet? How did micro organisms get enough oxygen to survive when the entire planet was frozen over? What can iron ore deposits tell us about life surviving when the entire planet was frozen over? Can life survive on a meteorite, the answer is surprising. How can a microbe be more suited to life on a meteorite than on earth?

1. Katharine J. Thompson, Paul A. Kenward, Kohen W. Bauer, Tyler Warchola, Tina Gauger, Raul Martinez, Rachel L. Simister, Céline C. Michiels, Marc Llirós, Christopher T. Reinhard, Andreas Kappler, Kurt O. Konhauser, Sean A. Crowe. Photoferrotrophy, deposition of banded iron formations, and methane production in Archean oceans. Science Advances, 2019; 5 (11): eaav2869 DOI: 10.1126/sciadv.aav2869
2. Maxwell A. Lechte, Malcolm W. Wallace, Ashleigh van Smeerdijk Hood, Weiqiang Li, Ganqing Jiang, Galen P. Halverson, Dan Asael, Stephanie L. McColl, Noah J. Planavsky. Subglacial meltwater supported aerobic marine habitats during Snowball Earth. Proceedings of the National Academy of Sciences, 2019; 201909165 DOI: 10.1073/pnas.1909165116
3. Tetyana Milojevic, Denise Kölbl, Ludovic Ferrière, Mihaela Albu, Adrienne Kish, Roberta L. Flemming, Christian Koeberl, Amir Blazevic, Ziga Zebec, Simon K.-M. R. Rittmann, Christa Schleper, Marc Pignitter, Veronika Somoza, Mario P. Schimak, Alexandra N. Rupert. Exploring the microbial biotransformation of extraterrestrial material on nanometer scale. Scientific Reports, 2019; 9 (1) DOI: 10.1038/s41598-019-54482-7

Episode 355 - Satellites keeping us safe on the ground

Satellites can help save lives down on earth, by helping us better respond in disasters. When a flood, tsunami or other disaster strikes, satellites can help emergency responders get where they need to be as fast as possible. Satellites can track floods in near real time and help shave minutes of disaster response times. Finding your way in a flood or fire can be tricky, but satellites can help direct emergency responders. Satellites can help track critical infrastructure like bridges or roads as they age. When a bridge fails it can be a tragedy, but satellites can help give an early warning. When we dig big tunnels we can disturb structures and buildings, so how can we use satellites to avoid a disaster.

References:

1. Perry C. Oddo, John D. Bolten. The Value of Near Real-Time Earth Observations for Improved Flood Disaster Response. Frontiers in Environmental Science, 2019; 7 DOI: 10.3389/fenvs.2019.00127
2. Pietro Milillo, Giorgia Giardina, Daniele Perissin, Giovanni Milillo, Alessandro Coletta, Carlo Terranova. Pre-Collapse Space Geodetic Observations of Critical Infrastructure: The Morandi Bridge, Genoa, Italy. Remote Sensing, 2019; 11 (12): 1403 DOI: 10.3390/rs11121403

Episode 351 - A new dwarf planet and what makes an exoplanet habitable

What makes a dwarf planet not a planet? What are the rules governing the word planet? Just how many dwarf planets are out there in our solar system? How can we use telescopes and modelling to add or subtract a dwarf planet from that list? We've talked about Goldilocks zone exoplanets, but what about their ability to withstand space weather? What role does a star's magnetic field play in protecting a planet from damaging radiation? Does space weather need to be added to the exoplanet Goldilocks zone?

References:

1. P. Vernazza, L. Jorda, P. Ševeček, M. Brož, M. Viikinkoski, J. Hanuš, B. Carry, A. Drouard, M. Ferrais, M. Marsset, F. Marchis, M. Birlan, E. Podlewska-Gaca, E. Jehin, P. Bartczak, G. Dudzinski, J. Berthier, J. Castillo-Rogez, F. Cipriani, F. Colas, F. DeMeo, C. Dumas, J. Durech, R. Fetick, T. Fusco, J. Grice, M. Kaasalainen, A. Kryszczynska, P. Lamy, H. Le Coroller, A. Marciniak, T. Michalowski, P. Michel, N. Rambaux, T. Santana-Ros, P. Tanga, F. Vachier, A. Vigan, O. Witasse, B. Yang, M. Gillon, Z. Benkhaldoun, R. Szakats, R. Hirsch, R. Duffard, A. Chapman, J. L. Maestre. A basin-free spherical shape as an outcome of a giant impact on asteroid Hygiea. Nature Astronomy, 2019; DOI: 10.1038/s41550-019-0915-8
2. Alison O. Farrish, David Alexander, Mei Maruo, Marc DeRosa, Frank Toffoletto, Anthony M. Sciola. Characterizing the Magnetic Environment of Exoplanet Stellar Systems. The Astrophysical Journal, 2019; 885 (1): 51 DOI: 10.3847/1538-4357/ab4652

Episode 344 - Colliding galaxies, stellar foundires and the emptiness of space

We look at galactic events, where galaxies collide, stars form and emptiness of space. Space is so unfathomably huge, but its still possible for galaxies to collide. The Milky Way was formed through one of this violent collisions over 10 billion years ago. Space seems empty but there are sections of space that are emptier than others, the great Local Void around the Local group. Stars forming in galaxies rely on gas clouds, but what does it take to form a star? What do you need to really make a good nursery for stars?

1. R. Brent Tully, Daniel Pomarède, Romain Graziani, Hélène M. Courtois, Yehuda Hoffman, Edward J. Shaya. Cosmicflows-3: Cosmography of the Local Void. The Astrophysical Journal, 2019; 880 (1): 24 DOI: 10.3847/1538-4357/ab2597
2. Kazufumi Torii, Shinji Fujita, Atsushi Nishimura, Kazuki Tokuda, Mikito Kohno, Kengo Tachihara, Shu-ichiro Inutsuka, Mitsuhiro Matsuo, Mika Kuriki, Yuya Tsuda, Tetsuhiro Minamidani, Tomofumi Umemoto, Nario Kuno, Yusuke Miyamoto. FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45 m telescope (FUGIN). V. Dense gas mass fraction of molecular gas in the Galactic plane. Publications of the Astronomical Society of Japan, 2019; DOI: 10.1093/pasj/psz033
3. Carme Gallart, Edouard J. Bernard, Chris B. Brook, Tomás Ruiz-Lara, Santi Cassisi, Vanessa Hill, Matteo Monelli. Uncovering the birth of the Milky Way through accurate stellar ages with Gaia. Nature Astronomy, 2019; DOI: 10.1038/s41550-019-0829-5

Episode 338 - Exoplanets boiling and stretching, Goldilocks and Supernova

Boiling planets being stretched and squished. Tiny white dwarf stars going supernova. Goldilocks planets potentially with liquid water. Exoplanet hunting is now a lot easier with missions like TESS and veterans like Hubble. We look at some special cases, and how searching for 1 planet can uncover loads more. Sometimes planets are lurking in old observatory data, we just need to know where to look. Too hot, too cold, GJ357 potentially has a planet that's just right with liquid water. What causes a White Dwarf to go supernova? It needs more than itself to kickstart it into a Type 1a nova...so where does the extra boost come from? Devouring another planet? Or another star?
References:

1. L. Kaltenegger, J. Madden, Z. Lin, S. Rugheimer, A. Segura, R. Luque, E. Palle, N. Espinoza. The Habitability of GJ 357 d Possible Climates and Observability. Astrophysical Journal Letters, 2019; (accepted) [link]
2. R. Luque, E. Pallé, D. Kossakowski, S. Dreizler, J. Kemmer, N. Espinoza. Planetary system around the nearby M dwarf GJ 357 including a transiting, hot, Earth-sized planet optimal for atmospheric characterization. Astronomy & Astrophysics, 2019; DOI: 10.1051/0004-6361/201935801
3. David K. Sing, Panayotis Lavvas, Gilda E. Ballester, Alain Lecavelier des Etangs, Mark S. Marley, Nikolay Nikolov, Lotfi Ben-Jaffel, Vincent Bourrier, Lars A. Buchhave, Drake L. Deming, David Ehrenreich, Thomas Mikal-Evans, Tiffany Kataria, Nikole K. Lewis, Mercedes López-Morales, Antonio García Muñoz, Gregory W. Henry, Jorge Sanz-Forcada, Jessica J. Spake, Hannah R. Wakeford. The Hubble Space Telescope PanCET Program: Exospheric Mg ii and Fe ii in the Near-ultraviolet Transmission Spectrum of WASP-121b Using Jitter Decorrelation. The Astronomical Journal, 2019; 158 (2): 91 DOI: 10.3847/1538-3881/ab2986
4. P J Vallely, M Fausnaugh, S W Jha, M A Tucker, Y Eweis, B J Shappee, C S Kochanek, K Z Stanek, Ping Chen, Subo Dong, J L Prieto, T Sukhbold, Todd A Thompson, J Brimacombe, M D Stritzinger, T W-S Holoien, D A H Buckley, M Gromadzki, Subhash Bose. ASASSN-18tb: a most unusual Type Ia supernova observed by TESS and SALT. Monthly Notices of the Royal Astronomical Society, 2019; 487 (2): 2372 DOI: 10.1093/mnras/stz1445

Lagrange Point Episode 334 - Hidden in empty space