Perfect

I have visited

you have visited

he has visited

we have visited

you have visited

they have visited

Past

I visited

you visited

he visited

we visited

you visited

they visited

Pluperfect

I had visited

you had visited

he had visited

we had visited

you had visited

they had visited

Present

I have visited

you have visited

he have visited

we have visited

you have visited

they have visited

Imperfect

I visited

you visited

he visited

we visited

you visited

they visited

Pluperfect

I had visited

you had visited

he had visited

we had visited

you had visited

they had visited

Conditional

Perfect

I would have visited

you would have visited

he would have visited

we would have visited

you would have visited

they would have visited

a little less htan 1

There is no solid proof aliens even exist much less have visited Earth.

no, 'visited' is past tense.

'have visited' is present perfect'

'had visited' is past perfect