The word 'dinosaur' doesn't actually appear in the Bible. That is because the word 'dinosaur' wasn't invented until the mid-1800s. Prior to that, dinosaurs were known as dragons.
So while the word "dinosaur" isn't in Scripture, dinosaurs may have actually been described in the Bible as Behemoth and Leviathan, both of which can be found in Job 40:15-24 and Job 41. Many scholars have explained or identified the creatures described in Job as a Nile crocodile or a hippopotamus. However, a close examination of this text reveals descriptions that match a sauropod (like the Apatosaurus) and a plesiosaur far better than a crocodile and hippo.
As dinosaurs were animals, they too were created on Day 6 along with all the other land animals (and humans). This also means that the dinosaur kinds were present on the Ark with Noah, surviving the Great Flood and afterward spreading out to reinhabit the Earth. This makes sense of the presence of dinosaur fossils on every continent - these are the fossilized remains of the animals buried by the Great Flood.
All around the world, nearly every culture has stories and legends of dragons. If you think about it, dragon legends may be nothing more than somewhat exaggerated or embellished traditions of dinosaurs, passed down orally from those that saw and experienced these magnificent creatures first hand.
There are several authenticated artifacts having images or representations of what appear to be dinosaurs as well. The stone carvings at ancient Khmer temples in Cambodia that any child would recognize as a stegosaur, ancient Native American petroglyphs that look like a sauropod, and an ancient Greek urn possibly depicting a mesosaur with other modern sea creatures, just to name a few. These ancient cultures likely had little to no knowledge of the fossil record, so how would they have concluded what animals from "millions" of years ago would have looked like? It is more likely that they witnessed first hand the existence of these creatures and recorded them just as they did other animals that they observed. Secularists too, have explanations for these images based upon their presuppositions, but these same artifacts fit perfectly well within the teachings of Scripture.
If you begin to look at the world through the lens of Scripture, you will unmistakenly find that the evidence (natural and man-made) that is available to everyone (believer and unbeliever) affirms what the Bible teaches. The Bible can always betrusted to be true and authoritative.
Comets cannot be older than thousands of years due to their composition of mostly ice, as they typically lose about 1% of their mass every time they orbit the sun. Astronomers know this, yet they also believe that the Solar System is billions of years old. Since comets cannot be millions of years old, many secular astronomers have hypothesized that the comets we see today must have entered the inner solar system relatively recently from a more stable orbit, beyond the eroding effects of the sun. This hypothesized locale is known as the Oort Cloud (named after Jan Oort). The Oort Cloud has never been observed. Science requires that all legitimate phenomena be observable, testable, repeatable, and confirmed by peer review. The Oort Cloud meets none of these criteria. How then can it be called scientific?
However, "young" comets fit perfectly well into the Biblical account of creation, as the universe is only thousands of years old, not millions and billions.
The Oort Cloud hypothesis should not be taught as fact in our schools.