Joseph Smith's most profound and enlightening sermon on the signs of the last days, given on the temple grounds at Nauvoo in April, 1843, demonstrates his views of the origin and nature of those signs, as well as our ability to recognize them for what they are.
"There will be wars and rumors of wars, signs in the heavens above and on the earth beneath, the sun turned into darkness and the moon to blood, earthquakes in divers places, the seas heaving beyond their bounds; … " (History of the Church, 5:337.)
Of particular interest is his addition of a truly remarkable sign to the customary list — one to which Latter-day Saints should give special heed. "… then will appear one grand sign of the coming of the Son of Man in heaven." (Ibid.) This is clearly a reiteration of the Savior’s statement in Matthew 24 wherein he said, "And then shall appear the sign of the Son of man in heaven …."
Until this last dispensation of the gospel, no other prophet or passage of scripture had added the superlative "grand sign." Typically, all the signs are given equal weight or value; none is designated as special or more notable. Indeed, the only other mention is found in modern revelation wherein a slightly altered version of the term is used. Speaking of the last days, the Lord declared to Joseph in December 1842, "And immediately there shall appear a great sign in heaven, and all people shall see it together." (Doctrine & Covenants 88:93.)
Indeed, Joseph may have intended that this sermon, given a mere four months after the revelation recorded in Doctrine & Covenants, reaffirm and amplify on that revelation since Section 88 is remarkable for its catalog of latter-day signs.
On that occasion, Joseph continued his sermon by explaining what that marvelous sign might be. "What will the world do? They will say it is a planet, a comet, &c. But the Son of Man will come as the sign of the coming of the Son of Man, which will be as the light of the morning cometh out of the east. (Ibid.)
It is a stunning statement, when carefully considered. The greatest or grandest of signs will be a comet or planet. Assumably, this comet or planet will be doing something well out of the ordinary to attract special attention.
Note that the Prophet is not saying the world’s assessment is incorrect, as some have supposed. Rather, he is merely noting that the worldly or scientific terminology for this eye-catching sign would be "a planet, a comet, &c."
In light of what modern science has discovered in recent years about rogue comets and asteroids, this observation by Joseph Smith is striking. Mention of this great or grand sign is unique to this dispensation and is therefore worthy of special attention by Mormons — especially in light of what occurred in the heavens a decade ago.
In July 1994, fragments of comet Shoemaker-Levy repeatedly slammed into the planet Jupiter, as forecast by astronomers. At least one of those impact sites left a pockmark on Jupiter's face that was larger than the Earth. Estimates were that the first fragment alone struck with the force of 200,000 megatons of explosive power! Nineteen more followed, leaving visible impact scars around Jupiter's southern hemisphere.
This was an unprecedented, historic, celestial event. Nothing even remotely as spectacular has occurred in our solar system since Galileo invented the telescope. From Joseph Smith’s time forward, scientists had utterly dismissed the possibility that comets or asteroids might menace the Earth. Even the prominent astronomer Carl Sagan denied the likelihood of cometary impact. As far as science was concerned, such nonsense was "impossible."
Due to comet Shoemaker/Levy, the scientific community did a conceptual about-face that was as dramatic as it was sweeping. They had been treated to a celestial visual aid of cosmic proportions; the "impossible" had occurred before their very eyes. There was no denying catastrophic impacts any longer.
As a result, today the idea of an impact dramatically altering Earth’s ecosystem is well accepted. Cosmic collisions do occur, scientists acknowledge, as in the instance of the dinosaurs’ extinction. Moreover, if it can happen to Jupiter, it can happen to the Earth.
Almost overnight, scientists began speaking of the threat posed by Earth-crossing asteroids and comets. NASA proposed a program and sought funding to find and track any object that might collide with the Earth.
A cosmic collision could result in a range of consequences, much like those signs listed by Joseph, from something no greater than any local disaster — as in an earthquake, flood or famine — to a worldwide event with long-term implications. The models proposed by researchers differ only in scale.
Even a moderate size impactor could ultimately lead to the death of at least one-fourth of the world's population. A near collision by a planet passing nearby us could be as devastating or worse, depending upon the proximity of the intruder. The extent of the damage would be determined by the size, composition, incoming velocity, angle and location — ocean or land, populated or unpopulated — of the impactor. For example, if the Tunguska meteorite of 1902, which exploded in the upper atmosphere without even hitting the ground, were to fall on Moscow today, the death toll would be about 9 million dead!
Especially significant is the fact that the "grand sign," — making an impact in the case of a comet, a very close pass or near miss in the case of a planet — would cause all the signs listed by Joseph Smith in his discourse. That is, the "grand sign" would be the direct cause of the other signs listed by the Prophet, as well as by the scriptures.
Everyone on the planet would be in peril.
The location of a strike would ultimately determine the nature of the aftermath, while a close planetary pass would cause uniform but devastating destruction worldwide. If the impact were an ocean strike, it would generate a tsunami ranging in size from a few feet up to hundreds of feet in height, with the potential of destroying up to 100 million people worldwide. A close pass would raise prodigious ocean tides drawn up by the gravitational pull of the offending planet, with very nearly the same effect as an ocean impact. This would be "the seas heaving beyond their bounds" Joseph described.
If it were a landfall, the shock wave would cause global geological stress that would certainly generate massive "earthquakes in divers places," as would a close pass by gravitational 'tugging' at the landmasses.
The ejecta from the impact or from colossal volcanic eruptions in the event of a planetary near miss would take the form of gas, dust and stones, which would be blown high into the atmosphere. The debris would fall back to earth in showers of hot stones, like so many artillery shells. Widespread rains of these hot stones would almost immediately create hemisphere-wide fires and destruction.
The dust would be transported around the Earth by high-altitude winds, casting the world into near-total gloom — "the sun turned into darkness — followed by freezing cold, leading to the suppression of photosynthesis for months, even years.
The gas released would eventually cause intense acid rain and destruction of the ozone layer, signs suggested elsewhere in scripture. Agriculture would collapse, resulting in famines, as suggested in prophecy, and the breakdown of global economic, social and political structures would result in "wars and rumors of wars," among other things.
Latter-day Saints' opinion on the subject of potential impacts, past and present, differs little from that of the general public. They see it as very unlikely. Yet, that probably should not be so, given the scriptural certainty of the last days and Joseph Smith’s enlightened statement regarding the last great sign being a comet or planet. He clearly held a view of history and prophecy that included disasters emanating from the heavens, which would have devastating effects here on Earth.
When we consider the magnitude and import of seeing a comet impact Jupiter in our own time as we approach the second coming, one wonders if this astronomical visual aid might not have been God's way of making a point, just as he gave a celestial sign to the Nephites prior to the Savior’s first coming. Have we been forewarned, just as were our Nephite cousins? Could it have been meant to awaken us from our apathetic complacency about the times we live in and the planet we live on? Should not Latter-day Saints — the "children of the light" — be the first to recognize the true import of this sign?
Remember, Joseph Smith placed great store in the validity of latter-day signs, especially those that can be described as planets or comets.
© Anthony E. Larson, 2003