शोध निकाल

visible during the day with naked eye when Sun is less than 10° above the horizon −2.50 Minimum brightness of new moon −2.45 Maximum brightness of Mercury...

the Dawn of Life. Boston. pp. 254–256. "The Day the Earth Nearly Died". Horizon. 2006-04-09 रोजी पाहिले. "Big crater seen beneath ice sheet".  . 2006-11-15...