Solstice Sun In Soft X-rays . ... This false-color image of the sun was made about 48 hours before the solstice in the light of soft (lower energy) X-rays by a telescope on board the space-based Yohkho solar observatory . The normally bright, visible solar surface or photosphere appears dark in X-ray light while active regions in the solar corona which lie above the photosphere are particularly X-ray bright. ... NASA Web Site Statements, Warnings, and Disclaimers . NASA Official: Jay Norris. ...