| Rank | Name | Date |
|---|---|---|
| 1 | Bill Nye | 2012-07-27 |
| 2 | Neil deGrasse Tyson | 2012-02-29 |
| 3 | Bill Nye | 2017-04-19 |
| 4 | Conan O'Brien | 2017-03-01 |
| 5 | Neil deGrasse Tyson | 2011-11-13 |
| 6 | Richard Dawkins | 2013-11-26 |
| 7 | Bill Nye | 2017-11-08 |
| 8 | Neil deGrasse Tyson | 2017-04-02 |
| 9 | Bill Nye | 2013-06-04 |
| 10 | Chris Hadfield | 2013-02-17 |
| 11 | Neil deGrasse Tyson | 2011-12-17 |
| 12 | Chris Hadfield | 2013-12-04 |
| 13 | Buzz Aldrin | 2014-07-08 |
| 14 | Richard Dawkins | 2016-05-27 |
| 15 | Bill Nye | 2014-11-05 |
| 16 | Michio Kaku | 2014-03-07 |
| 17 | Ron Garan | 2012-12-06 |
| 18 | David Attenborough | 2014-01-08 |
| 19 | Jane Goodall | 2017-09-13 |
| 20 | Neil deGrasse Tyson | 2013-08-04 |
| 21 | Buzz Aldrin | 2014-10-30 |
| 22 | Brian Krzanich | 2014-02-19 |
| 23 | Bill Nye | 2014-07-15 |
| 24 | Mark Rober | 2019-12-23 |
| 25 | Tim Berners-Lee | 2014-03-12 |
| 26 | Norman Ohler | 2017-03-07 |
| 27 | Scott Kelly | 2016-01-23 |
| 28 | CodyDon Reeder | 2018-02-07 |
| 29 | Mason Peck | 2013-05-20 |
| 30 | Bob Metcalfe | 2013-05-21 |
| 31 | Chris Hadfield | 2012-12-13 |
| 32 | Steve Pinker | 2013-03-12 |
| 33 | Scott Kelly | 2018-04-26 |
| 34 | Al Worden | 2016-08-11 |