By Dr Douglas Palmer, Ph.D. (University of Cambridge)
By James Hansen
By Kerrod, Robin
By Rhodes
By Simon Mitton
By Carl Sagan
By Joseph Silk (, Savilian Professor of Astronomy, University of Oxford)
By Jane Gregory (, Lecturer in Science Communication and Science Policy, University College London)
By Sir Fred Hoyle
By Christophe Galfard
By Roger Penrose
By Nirmala Nataraj, NASA, Bill Nye
By Joao Magueijo
By CBE, DSC, FRAS, Sir Patrick Moore
By Alex Gordon Smith
By Lisa Randall
By Iain Nicholson
By Patrick Moore, Sir, Moore, Sir Patrick
By Eklöf, Johan, DeNoma, Dr. Elizabeth
By The German Space Centre
By Aughton, Peter
By Barrow, John D.
By Pirani, Felix
By Dunlop, Storm, Tirion, Wil, Royal Observatory Greenwich, Collins Astronomy
By Kolb, Rocky
By BULKELEY, Rip, Thompson, E. P., Ben
By Immanuel Velikovsky, Velikovsky, Immanuel
By Kaler, James B.