A darkening of the sun and moon. Stars falling from the heavens. Powers of the heavens shaking. The sounding of a great trumpet. Jesus said these will precede His return to earth in the last days; Bro. Jeff gives more Biblical detail here.
Matthew 24:29-31 KJV
29 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: 30 And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory. 31 And he shall send his angels with a great sound of a trumpet, and they shall gather together his elect from the four winds, from one end of heaven to the other.
12 And I beheld when he had opened the sixth seal, and, lo, there was a great earthquake; and the sun became black as sackcloth of hair, and the moon became as blood;
12 And the fourth angel sounded, and the third part of the sun was smitten, and the third part of the moon, and the third part of the stars; so as the third part of them was darkened, and the day shone not for a third part of it, and the night likewise.
10 And the fifth angel poured out his vial upon the seat of the beast; and his kingdom was full of darkness; and they gnawed their tongues for pain,
13 And the stars of heaven fell unto the earth, even as a fig tree casteth her untimely figs, when she is shaken of a mighty wind.
10 And the third angel sounded, and there fell a great star from heaven, burning as it were a lamp, and it fell upon the third part of the rivers, and upon the fountains of waters; 11 And the name of the star is called Wormwood: and the third part of the waters became wormwood; and many men died of the waters, because they were made bitter.
4 And, being assembled together with [them], commanded them that they should not depart from Jerusalem, but wait for the promise of the Father, which, [saith he], ye have heard of me. 5 For John truly baptized with water; but ye shall be baptized with the Holy Ghost not many days hence. 6 When they therefore were come together, they asked of him, saying, Lord, wilt thou at this time restore again the kingdom to Israel? 7 And he said unto them, It is not for you to know the times or the seasons, which the Father hath put in his own power. 8 But ye shall receive power, after that the Holy Ghost is come upon you: and ye shall be witnesses unto me both in Jerusalem, and in all Judaea, and in Samaria, and unto the uttermost part of the earth. 9 And when he had spoken these things, while they beheld, he was taken up; and a cloud received him out of their sight. 10 And while they looked stedfastly toward heaven as he went up, behold, two men stood by them in white apparel; 11 Which also said, Ye men of Galilee, why stand ye gazing up into heaven? this same Jesus, which is taken up from you into heaven, shall so come in like manner as ye have seen him go into heaven.
7 Behold, he cometh with clouds; and every eye shall see him, and they [also] which pierced him: and all kindreds of the earth shall wail because of him. Even so, Amen.
13 I saw in the night visions, and, behold, [one] like the Son of man came with the clouds of heaven, and came to the Ancient of days, and they brought him near before him. 14 And there was given him dominion, and glory, and a kingdom, that all people, nations, and languages, should serve him: his dominion [is] an everlasting dominion, which shall not pass away, and his kingdom [that] which shall not be destroyed.
18 And Jesus came and spake unto them, saying, All power is given unto me in heaven and in earth.
11 And I saw heaven opened, and behold a white horse; and he that sat upon him [was] called Faithful and True, and in righteousness he doth judge and make war. 12 His eyes [were] as a flame of fire, and on his head [were] many crowns; and he had a name written, that no man knew, but he himself. 13 And he [was] clothed with a vesture dipped in blood: and his name is called The Word of God. 14 And the armies [which were] in heaven followed him upon white horses, clothed in fine linen, white and clean. 15 And out of his mouth goeth a sharp sword, that with it he should smite the nations: and he shall rule them with a rod of iron: and he treadeth the winepress of the fierceness and wrath of Almighty God. 16 And he hath on [his] vesture and on his thigh a name written, KING OF KINGS, AND LORD OF LORDS. 17 And I saw an angel standing in the sun; and he cried with a loud voice, saying to all the fowls that fly in the midst of heaven, Come and gather yourselves together unto the supper of the great God; 18 That ye may eat the flesh of kings, and the flesh of captains, and the flesh of mighty men, and the flesh of horses, and of them that sit on them, and the flesh of all [men, both] free and bond, both small and great. 19 And I saw the beast, and the kings of the earth, and their armies, gathered together to make war against him that sat on the horse, and against his army. 20 And the beast was taken, and with him the false prophet that wrought miracles before him, with which he deceived them that had received the mark of the beast, and them that worshipped his image. These both were cast alive into a lake of fire burning with brimstone. 21 And the remnant were slain with the sword of him that sat upon the horse, which [sword] proceeded out of his mouth: and all the fowls were filled with their flesh.
1 And after six days Jesus taketh Peter, James, and John his brother, and bringeth them up into an high mountain apart, 2 And was transfigured before them: and his face did shine as the sun, and his raiment was white as the light. 3 And, behold, there appeared unto them Moses and Elias talking with him. 4 Then answered Peter, and said unto Jesus, Lord, it is good for us to be here: if thou wilt, let us make here three tabernacles; one for thee, and one for Moses, and one for Elias. 5 While he yet spake, behold, a bright cloud overshadowed them: and behold a voice out of the cloud, which said, This is my beloved Son, in whom I am well pleased; hear ye him. 6 And when the disciples heard [it], they fell on their face, and were sore afraid.
14 And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth.
2 Peter 1:16-18
16 For we have not followed cunningly devised fables, when we made known unto you the power and coming of our Lord Jesus Christ, but were eyewitnesses of his majesty. 17 For he received from God the Father honour and glory, when there came such a voice to him from the excellent glory, This is my beloved Son, in whom I am well pleased. 18 And this voice which came from heaven we heard, when we were with him in the holy mount.
23 And the city had no need of the sun, neither of the moon, to shine in it: for the glory of God did lighten it, and the Lamb [is] the light thereof.
27 For the Son of man shall come in the glory of his Father with his angels; and then he shall reward every man according to his works.
10 And I will pour upon the house of David, and upon the inhabitants of Jerusalem, the spirit of grace and of supplications: and they shall look upon me whom they have pierced, and they shall mourn for him, as one mourneth for [his] only [son], and shall be in bitterness for him, as one that is in bitterness for [his] firstborn.
Matthew 13:40-43, 49-50
40 As therefore the tares are gathered and burned in the fire; so shall it be in the end of this world. 41 The Son of man shall send forth his angels, and they shall gather out of his kingdom all things that offend, and them which do iniquity; 42 And shall cast them into a furnace of fire: there shall be wailing and gnashing of teeth. 43 Then shall the righteous shine forth as the sun in the kingdom of their Father. Who hath ears to hear, let him hear. … 49 So shall it be at the end of the world: the angels shall come forth, and sever the wicked from among the just, 50 And shall cast them into the furnace of fire: there shall be wailing and gnashing of teeth.