Yes. Mars Market is one of three entries on this knowledge base that natively accepts Litecoin (the others being Nexus and Anubis).
When LTC makes sense
Litecoin is useful when you have a small deposit and Bitcoin network fees would eat too much of it. LTC fees are pennies and confirmations are faster, both because of network design and because the marketplace is willing to credit balances after fewer confirmation blocks than for BTC.
Privacy caveat
Litecoin’s privacy properties are similar to Bitcoin’s — a public ledger, traceable across exchanges. If privacy is the reason you are on Tor, default to Monero instead. See which Tor markets accept Litecoin.
Wallet recommendations
Any non-custodial Litecoin wallet that gives you the seed phrase is fine. Litecoin Core is the reference; Electrum-LTC is lightweight and quick to set up. Avoid exchange-custodial wallets for darknet deposits — the exchange logs every transaction, which defeats the privacy posture you started with.