The Bible promises us that there would be signs in the heavens as the day of the Lord approaches - for both a blessing of deliverance, and a warning to his people not to forget Him.
For many, the Son of God becomes 'eclipsed' in their hearts from the busy-ness of this world; but God's word encourages us that when we see these heavenly signs come to pass, to:
"Look up...for your redemption draweth nigh." (Luke 21:28)
These signs are even set in the heavens by a loving God for the very reason of bringing our attention back to Him:
"There shall be signs in the sun, and in the moon, and in the stars; and upon the earth distress of nations, with perplexity; the sea and the waves roaring; Men's hearts failing them for fear, and for looking after those things which are coming on the earth: for the powers of heaven shall be shaken.
And then shall they see the Son of man coming in a cloud with power and great glory. And when these things begin to come to pass, then look up, and lift up your heads; for your redemption draweth nigh." (Luke 21:25-28)
Below are a few more Bible verses that speak of the Signs in the Heavens, and that also speak specifically regarding the Sun and the Moon being 'darkened' - as with a Total Eclipse of the Sun, the 'Son of Righteousness' - both in biblical history and in prophecy to come:
"And I will shew wonders in the heavens and in the earth, blood, and fire, and pillars of smoke. The sun shall be turned into darkness, and the moon into blood, before the great and terrible day of the Lord come. And it shall come to pass, that whosoever shall call on the name of the Lord shall be delivered."
"The sun and the moon shall be darkened, and the stars shall withdraw their shining."
"Behold, the day of the Lord cometh, cruel both with wrath and fierce anger, to lay the land desolate: and he shall destroy the sinners thereof out of it. For the stars of heaven and the constellations thereof shall not give their light: the sun shall be darkened in his going forth, and the moon shall not cause her light to shine. And I will punish the world for their evil, and the wicked for their iniquity; and I will cause the arrogancy of the proud to cease, and will lay low the haughtiness of the terrible."
"For, behold, the day cometh, that shall burn as an oven; and all the proud, yea, and all that do wickedly, shall be stubble: and the day that cometh shall burn them up, saith the Lord of hosts, that it shall leave them neither root nor branch. "But unto you that fear my name shall the Sun of righteousness arise with healing in his wings; and ye shall go forth, and grow up as calves of the stall."
"Immediately after the tribulation of those days shall the sun be darkened, and the moon shall not give her light, and the stars shall fall from heaven, and the powers of the heavens shall be shaken."
"But in those days, after that tribulation, the sun shall be darkened, and the moon shall not give her light."
And the sun was darkened, and the veil of the temple was rent in the midst."
"Yet the Lord will command his lovingkindness in the day time, and in the night his song shall be with me, and my prayer unto the God of my life."