How to camouflage a meteor

What requirements would a meteor have to satisfy, to approach Earth unrecognized until hitting the atmosphere and cause climatic changes after the impact?

• The meteor should have at least a circumference of 500 meters at impact to cause something.
• It might have to hit earth at land because at sea there would be tsunamis and mostly no climatic change.
• The climatic changes should be an impact winter but if there are other ideas they are very welcome!
• If camouflaging the meteor is naturally possible then i would prefer this way. If not we are at the actual technology level.

Edits:

• The Meteor should remain undiscovered until the discoverer has no time left to make his discovery public before the impact.

posted over 8 years ago

if-trubite‭

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