Breakthrough Discuss 2021 (VIRTUAL)

“The Alpha Centauri System: A Beckoning Neighbor”


April 12-13, 2021 (Monday, Tuesday)

Public Livestream

The conference can be watched live at

(registered attendees, please use the ‘Attendee Zoom Link’ you received via email)

Keynotes – Presenters – Co-Chairs – Hosts

Conference abstracts, biographies and pictures are available at this link:

Day One (April 12)

All times Pacific Time (PDT)

08:00 Welcome – Hosts Charles Alcock, Penny Boston, Burkhard Militzer, Jamie Drew, S. Pete Worden
08:10 Keynote: Celebrating the opening of the Space Age from Gagarin to the Big Bang John Grunsfeld
08:40 Session One: Mapping the Alpha Centauri System Chairs: Olivier Guyon, Sara Seager
08:50 Batting Next in AAA: Alpha Cen ALMA Astrometry Presenter 1: Rachel Akeson
09:10 Getting to know the Neighbours: Earth analog planets with the TOLIMAN telescope Presenter 2: Celine Boehm
09:30 Twirling Dancers: Where in Space is Alpha Centauri? Presenter 3: Pierre Kervella
09:50 Imaging Habitable-zone Exoplanets with Breakthrough Watch/NEAR Presenter 4: Kevin Wagner
10:10 Session One: Q&A Chairs: Olivier Guyon, Sara Seager
10:55 Break
11:25 Session Two: Prospects for Life at Alpha Centauri Chairs: Lisa Kaltenegger, Andrew Siemion
11:35 In a Different Light: Life Around Other Stars Presenter 5: Antigona Segura
11:55 Earth Over 4 Billion Years as an Exoplanet Presenter 6: Sarah Rugheimer
12:15 A Case for Technosignatures Around Alpha Centauri? Presenter 7: Brian Lacki
12:35 The Story of blc1: Breakthrough Listen’s First Signal-of-Interest Presenter 8: Sofia Sheikh
12:55 Session Two: Q&A Chairs: Lisa Kaltenegger, Andrew Siemion
13:40 Concluding Remarks and Adjourn Day One

Yuri’s Night Panel (April 12)

All times Pacific Time (PDT)

17:00 Welcome – Yuri's Night Panel Discussion Moderator: Sara Seager
17:10 Panel Discussion: Gagarin, Venus and beyond Panelist 1: Bethany Ehlmann
Panelist 2: David Grinspoon
Panelist 3: Janusz Petkowski
Panelist 4: John Grunsfeld
17:55 Yuri's Night Discussion Q&A
18:15 Concluding Remarks

Day Two (April 13)

All times Pacific Time (PDT)

08:00 Welcome – Hosts Charles Alcock, Penny Boston, Burkhard Militzer, Jamie Drew, S. Pete Worden
08:10 Keynote: Exploring options for nanogram-scale fractional-lightspeed probe capable of landing, limited-growth, multisensor-imaging & IR-communications George Church
08:40 Session Three: Missions to Alpha Centauri Chairs: Harry Atwater, Kerri Cahoy
08:50 Light Sailing to Interstellar Distances Presenter 9: Artur Davoyan
09:10 Getting to Know Your Neighbor: Observations of the Local Interstellar Medium Presenter 10: Stefanie Milam
09:30 Fusion Proposal for Alpha Centauri Missions Presenter 11: Michael Paluszek
09:50 Current State of Deep Space Optical Communications Presenter 12: Tom Roberts
10:10 Session Three: Q&A Chairs: Harry Atwater, Kerri Cahoy
10:55 Concluding Remarks

Registered Attendance

Virtual attendance to Breakthrough Discuss 2021 via Zoom is requested if you received an invitation. Make sure to register at the site provided in the invitation. This will enable invited participants to take part in the Q/A sections of the schedule.

Otherwise, the public is welcome to watch the conference at Questions will be taken from the public as well as from invited guests.

Conference Theme

“The Alpha Centauri System: A Beckoning Neighbor”


Imagination will often carry us to worlds that never were. But without it we go nowhere.

– Carl Sagan

As the closest star system and planetary system to our own, at 4.37 light-years (1.34 parsecs), Alpha Centauri is naturally an object of interest. But its central role in a series of recent scientific discoveries makes it even more intriguing.

The Alpha Centauri system consists of two sun-like stars – α Centauri A (Rigel Kentaurus) and α Centauri B (Toliman) – and a red dwarf, Centauri C (Proxima Centauri). In the past few years several planets have been confirmed orbiting Proxima Centauri; one appears to be Earth-sized and in the star’s “habitable zone.” There has even been a detection of narrow-band radio signals from the direction of the dwarf star. Although these signals are most likely terrestrial interference, they have reignited an interest in Alpha Centauri across space science. And recent results suggest the possible presence of a giant planet in the habitable zone of Rigel Kentaurus (α Centauri A). Space and ground-based programs are underway to further study and confirm planets in the system. Furthermore, a number of promising approaches to probe missions to the system later in the century are now in development.

This year's virtual edition of Breakthrough Discuss 2021 challenges us to consider:

  1. Leading methods for mapping the system
  2. Prospects for life in the system
  3. State-of-the-art technologies enabling missions to the system

Session One

Mapping the Alpha Centauri System

Chairs: Olivier Guyon, Sara Seager


  • Rachel Akeson, Caltech
  • Celine Boehm, University of Sydney
  • Pierre Kervella, Paris Observatory
  • Kevin Wagner, University of Arizona

Considerable progress has been made in the development of new instruments for detecting and observing exoplanets, both on the ground (Extremely Large Telescopes – ELTs) and in space (astrometric and direct imaging systems). New approaches from deep in space – including using the sun as a gravitational lens – are being designed. In this session we will review these approaches and discuss when definitive answers about the Alpha Centauri system might be available.

Session Two

Prospects for Life at Alpha Centauri

Chairs: Lisa Kaltenegger, Andrew Siemion


  • Brian Lacki, UC Berkeley
  • Sarah Rugheimer, Oxford University
  • Antigona Segura, National Autonomous University of Mexico
  • Sofia Sheikh, UC Berkeley

With the discovery of several planets, and the likely presence of more, the possibilities for life in the Alpha Centauri system are growing more credible. Although significant stellar activity in the system is known, perhaps complicating the retention of water and the evolution of surface life, the system is estimated to be slightly older than our Sun, meaning there may have been ample time for adaptation to a harsh radiation environment. In our own Solar System, we believe that life may exist in other places other than on Earth, such as under ice crusts on outer Solar System moons, and in cold atmospheres such as Titan. How do we look for evidence of such diverse environments in the Alpha Centauri system?

There have even been narrow-band radio signals detected from the direction of Proxima Centauri. Although these signals are most likely due to terrestrial interference, they have reignited an interest in the Alpha Centauri system across space science. So, how do we search for, or rule out, the presence of intelligent life in that system?

Session Three

Missions to Alpha Centauri

Chairs: Kerri Cahoy, Harry Atwater


  • Artur Davoyan, UCLA
  • Stefanie Milam, NASA Goddard
  • Michael Paluszek, Princeton Satellite System
  • Tom Roberts, NASA JPL

For most of the space age, it has been considered nearly impossible to mount missions of any sort traversing the 25 trillion miles to the Alpha Centauri system. The landscape of possibilities is now rapidly changing. Space agencies such as NASA are funding concept studies for Alpha Centauri missions later in this century. Meanwhile privately funded initiatives, such as the Breakthrough Initiatives and the new Limitless Space Institute, are also funding various approaches that could enable interstellar probes within the Century. What are the candidate technologies and how feasible are they?

Yuri’s Night Panel Discussion

An evening ‘Yuri’s Night’ event (Monday, April 12) will be hosted by S. Pete Worden, Executive Director of the Breakthrough Initiatives.

April 12, 2021 marks the 60th anniversary of Yuri Gagarin’s voyage into space. It was an epochal moment for humanity – the day when we stepped out from our home planet and became a spacefaring species. Since then, we have explored throughout the Solar System. Of particular interest at the beginning of humanity’s space science adventures, as well as more recently, is the planet Venus. This panel will take us from Gagarin to Venus and beyond.


  • Bethany Ehlmann
  • David Grinspoon
  • Janusz Petkowski
  • Sara Seager (moderator/panelist)

Panel Abstract:

Alpha Centauri Trinary System (with Proxima Centauri) has known and suspected planetary companions including the closest exoplanet to Earth. The diversity of exoplanets is simply staggering - different, sizes, masses orbits and surely surface and atmospheric environments, but difficult to study. We do not have to look away from our own Solar System to study unique and alien environments. Venus can be considered as "an exoplanet next door", a planet very unique and distinct from any other in our Solar System, with a possibly tumultuous geological history (perhaps including once habitable water oceans) and a tantalizing albeit speculative prospects for aerial biosphere in its mysterious permanent clouds.


Breakthrough Discuss 2021 is co-hosted by:

  • NASA Ames Research Center, Penny Boston
  • UC Berkeley Earth & Planetary Science, Burkhard Militzer
  • Harvard-Smithsonian Center for Astrophysics, Charles Alcock
  • Breakthrough Initiatives (sponsor), S. Pete Worden


  • Jamie Drew, Breakthrough Initiatives
  • S. Pete Worden, Breakthrough Initiatives

Past Content

Content and videos from previous years are available here:

Code of Conduct

The Breakthrough Discuss conference is dedicated to fostering a safe environment where ideas flow freely, which means ensuring a harassment-free conference experience for all in attendance. No harassment of any kind towards any conference participants (including venue staff, etc.) will be tolerated during conference programming, breaks, or at any other conference-related event(s). Harassing behaviors include, but are not limited to, offensive verbal comments related to gender, sexual orientation, race, age, religion, disability, physical appearance, national origin, etc., as well as deliberate intimidation; harassing photography, recording, or postings; sustained disruption of talks or other events; inappropriate physical contact; and unwelcome sexual attention. If a participant engages in any harassing behavior, event organizers retain the right to take any actions to maintain a welcoming, safe environment for all participants. These actions include, but are not limited to, warning the alleged offender or expulsion from the conference and any associated event. If anyone experiences or witnesses any form of harassment at any point during any of the conference events, please contact:


The Breakthrough Initiatives

The Breakthrough Initiatives were founded in 2015 to explore the Universe, seek scientific evidence of life beyond Earth, and encourage public debate from a planetary perspective.

Breakthrough Discuss

Breakthrough Discuss is an annual academic conference focused on life in the Universe and novel ideas for space exploration.